BOUDREAU, Justice:
I 1 This is an appeal from a judgment on a Jury verdict in favor of defendant, Alfalfa Electric Cooperative, Inc. (AEC), in a negligence suit, certified as a class action. Plaintiffs, Rosemary Bouziden, et al., as individuals and representatives of approximately 150 families (plaintiffs), sought damages for loss of property due to a wildfire that spread over some 80,000 acres. Three questions are presented on certiorari: 1) Did AEC owe a non-delegable duty of care to the plaintiffs imposed either by the law of easements or because AEC was engaged in an inherently dangerous activity; 2) Did the trial court correctly allow the jury to decide whether an independent-contractor relationship existed between AEC and O0 & M; and 3) Did the trial court err by instructing the jury on independent, intervening cause? We answer the first question in the negative and the second and third in the affirmative. Accordingly, we vacate the opinion of the Court of Civil Appeals, Division I, and reverse the judgment of the district court and remand this cause for further proceedings consistent with this opinion.
I. Factual Background
12 This negligence class action arose out of the following basic facts. Since 1978, AEC had contracted with O0 & M Power Line Construction Co. (0 & M) to replace its utility poles. For several years, the contract between AEC and O & M was in writing. For 1996, the written contract had been orally extended. The basic terms of the contract provided that AEC would identify the poles to be replaced and O & M would perform the work at its discretion; AEC would supply the new utility poles and O & M would provide all necessary tools, equipment, and labor; O0 & M would be paid for each completed project upon AEC's inspection and approval of the work; and either party could terminate the contract at will.
13 On February 22, 1996, O & M was changing out utility poles in a branch line off ABC's main transmission line in Woods County, Oklahoma. The branch line was on [454]*454AEC's easement running through rangeland approximately fifteen miles north of Freedom, Oklahoma. The line had not been energized for about two years. ~
T4 The job required a digger truck, a large truck equipped with a large auger or digger unit, an overhead boom, and stabilizing outriggers. To get to the utility poles, the truck had to traverse rough terrain, with steep canyons and thickets O & M positioned the truck and then used a winch to position the new poles in front of the truck. Shortly thereafter, a fire started underneath the truck. Attempts to drive the truck over the poles were unsuccessful. The truck ignited and the fire spread to the surrounding brush and grass.
15 The conditions in the area were near drought and 0 & M could not extinguish the fire. With the assistance of the Freedom Volunteer Fire Department, the fire was nearly contained. However, the wind speed increased and the fire escaped the fire breaks. The fire spread across approximately 80,000 acres of extremely dry rangeland and crop land in northern Woods County, Oklahoma, and southern Comanche County and Barber County, Kansas, before it was ultimately contained some two days later.
T6 This negligence action was filed to recover damages for loss of buildings, fences, livestock, machinery and equipment, crops, and native grassland caused by the wildfire. AEC and 0 & M were named as defendants. The action was brought on behalf of the plaintiffs as individuals and as representatives of approximately 150 families who suffered loss caused by the wildfire. The trial court certified the class and the plaintiffs/appellants as class representatives. Prior to trial, 0 & M's liability insurance carrier paid an amount equal to the policy limits into the court and O & M was dismissed as a party defendant.
T7 Before the trial court, plaintiffs contended that, as a matter of law, ABC's responsibility for the performance of work on its easement was not delegable to a third-party contractor and requested a jury instruction that AEC was liable for the negligent acts of 0 & M. The court refused to give the instruction. Instead, the trial court instructed the jury on the basic elements of an independent contractor relationship and the general rule that one is not liable for the acts and omissions of an independent contractor. The jury returned a verdict in favor of AEC and the trial court entered judgment thereon. Plaintiffs timely appealed.
T8 In their petition in error, plaintiffs contended that the trial court erred by failing to hold, as a matter of law, that AEC's responsibility for the manner in which work was performed on its easement and right of way could not be avoided by delegating the work to a third party. Plaintiffs also attacked the sufficiency of the evidence produced at trial to support a finding that AEC and O & M entered into an independent contractor relationship. Finally, plaintiffs argued that the trial court erred in instructing on the issue of intervening cause.
T9 In support of the argument that AEC could not avoid liability by delegating the work to an independent contractor, plaintiffs relied upon the "non-delegable duty exception" to the independent-contractor tort rule expressed in Minnetonka Oil Co. v. Haviland, 55 Okla. 43, 155 P. 217 (1916), and its progeny Shell Pipe Line Corp. v. Curtis, 1955 OK 212, 287 P.2d 681, and Cities Service Gas Company v. Christian, 1957 OK 247, 316 P.2d 1113, 1115. While recognizing that these cases involved claims by the holders of the servient estate, plaintiffs argued that Oklahoma Ry. Co. v. Boyd, 140 Okla. 45, 282 P. 157 (1929), extended the non-delegable nature of the duty, not only to the holder of the servient estate, but to all other third parties.
T{10 In response, AEC contended that Minnetonka and its progeny impose a non-delegable duty upon the dominant estate holder to use the easement in a manner that will not cause harm to the servient estate holder only. AEC argued that the holding in Boyd is premised upon the law relating to riparian landowners and not the law of easements.
{11 The Court of Civil Appeals held that AEC owed a non-delegable duty of care to any third party and the duty of care could not be delegated to an independent contrac[455]*455tor. While acknowledging that most of the easement cases discussing non-delegable duties involved claims by owners of the ser-vient estate against the dominant tenant, the Court of Civil Appeals observed that none of those cases expressly limited its pronouncement to claims for damages suffered by the servient estate holders. The Court of Civil Appeals concluded that the trial court should have applied Boyd. Recognizing that 0 & M's status as an independent contractor and AEC's vicarious liability for 0 & M's negli-genee were the central factual and legal issues at trial, the Court of Civil Appeals found that failure to properly instruct the jury very probably affected the result and reversed the judgment entered on the jury verdict. The Court of Civil Appeals did not consider the issues raised and argued by plaintiffs concerning the status of the relationship between AEC and 0 & M and the insufficiency of the evidence to allow an intervening cause instruction. We granted AEC's petition for writ of certiorari.
II.
Free access — add to your briefcase to read the full text and ask questions with AI
BOUDREAU, Justice:
I 1 This is an appeal from a judgment on a Jury verdict in favor of defendant, Alfalfa Electric Cooperative, Inc. (AEC), in a negligence suit, certified as a class action. Plaintiffs, Rosemary Bouziden, et al., as individuals and representatives of approximately 150 families (plaintiffs), sought damages for loss of property due to a wildfire that spread over some 80,000 acres. Three questions are presented on certiorari: 1) Did AEC owe a non-delegable duty of care to the plaintiffs imposed either by the law of easements or because AEC was engaged in an inherently dangerous activity; 2) Did the trial court correctly allow the jury to decide whether an independent-contractor relationship existed between AEC and O0 & M; and 3) Did the trial court err by instructing the jury on independent, intervening cause? We answer the first question in the negative and the second and third in the affirmative. Accordingly, we vacate the opinion of the Court of Civil Appeals, Division I, and reverse the judgment of the district court and remand this cause for further proceedings consistent with this opinion.
I. Factual Background
12 This negligence class action arose out of the following basic facts. Since 1978, AEC had contracted with O0 & M Power Line Construction Co. (0 & M) to replace its utility poles. For several years, the contract between AEC and O & M was in writing. For 1996, the written contract had been orally extended. The basic terms of the contract provided that AEC would identify the poles to be replaced and O & M would perform the work at its discretion; AEC would supply the new utility poles and O & M would provide all necessary tools, equipment, and labor; O0 & M would be paid for each completed project upon AEC's inspection and approval of the work; and either party could terminate the contract at will.
13 On February 22, 1996, O & M was changing out utility poles in a branch line off ABC's main transmission line in Woods County, Oklahoma. The branch line was on [454]*454AEC's easement running through rangeland approximately fifteen miles north of Freedom, Oklahoma. The line had not been energized for about two years. ~
T4 The job required a digger truck, a large truck equipped with a large auger or digger unit, an overhead boom, and stabilizing outriggers. To get to the utility poles, the truck had to traverse rough terrain, with steep canyons and thickets O & M positioned the truck and then used a winch to position the new poles in front of the truck. Shortly thereafter, a fire started underneath the truck. Attempts to drive the truck over the poles were unsuccessful. The truck ignited and the fire spread to the surrounding brush and grass.
15 The conditions in the area were near drought and 0 & M could not extinguish the fire. With the assistance of the Freedom Volunteer Fire Department, the fire was nearly contained. However, the wind speed increased and the fire escaped the fire breaks. The fire spread across approximately 80,000 acres of extremely dry rangeland and crop land in northern Woods County, Oklahoma, and southern Comanche County and Barber County, Kansas, before it was ultimately contained some two days later.
T6 This negligence action was filed to recover damages for loss of buildings, fences, livestock, machinery and equipment, crops, and native grassland caused by the wildfire. AEC and 0 & M were named as defendants. The action was brought on behalf of the plaintiffs as individuals and as representatives of approximately 150 families who suffered loss caused by the wildfire. The trial court certified the class and the plaintiffs/appellants as class representatives. Prior to trial, 0 & M's liability insurance carrier paid an amount equal to the policy limits into the court and O & M was dismissed as a party defendant.
T7 Before the trial court, plaintiffs contended that, as a matter of law, ABC's responsibility for the performance of work on its easement was not delegable to a third-party contractor and requested a jury instruction that AEC was liable for the negligent acts of 0 & M. The court refused to give the instruction. Instead, the trial court instructed the jury on the basic elements of an independent contractor relationship and the general rule that one is not liable for the acts and omissions of an independent contractor. The jury returned a verdict in favor of AEC and the trial court entered judgment thereon. Plaintiffs timely appealed.
T8 In their petition in error, plaintiffs contended that the trial court erred by failing to hold, as a matter of law, that AEC's responsibility for the manner in which work was performed on its easement and right of way could not be avoided by delegating the work to a third party. Plaintiffs also attacked the sufficiency of the evidence produced at trial to support a finding that AEC and O & M entered into an independent contractor relationship. Finally, plaintiffs argued that the trial court erred in instructing on the issue of intervening cause.
T9 In support of the argument that AEC could not avoid liability by delegating the work to an independent contractor, plaintiffs relied upon the "non-delegable duty exception" to the independent-contractor tort rule expressed in Minnetonka Oil Co. v. Haviland, 55 Okla. 43, 155 P. 217 (1916), and its progeny Shell Pipe Line Corp. v. Curtis, 1955 OK 212, 287 P.2d 681, and Cities Service Gas Company v. Christian, 1957 OK 247, 316 P.2d 1113, 1115. While recognizing that these cases involved claims by the holders of the servient estate, plaintiffs argued that Oklahoma Ry. Co. v. Boyd, 140 Okla. 45, 282 P. 157 (1929), extended the non-delegable nature of the duty, not only to the holder of the servient estate, but to all other third parties.
T{10 In response, AEC contended that Minnetonka and its progeny impose a non-delegable duty upon the dominant estate holder to use the easement in a manner that will not cause harm to the servient estate holder only. AEC argued that the holding in Boyd is premised upon the law relating to riparian landowners and not the law of easements.
{11 The Court of Civil Appeals held that AEC owed a non-delegable duty of care to any third party and the duty of care could not be delegated to an independent contrac[455]*455tor. While acknowledging that most of the easement cases discussing non-delegable duties involved claims by owners of the ser-vient estate against the dominant tenant, the Court of Civil Appeals observed that none of those cases expressly limited its pronouncement to claims for damages suffered by the servient estate holders. The Court of Civil Appeals concluded that the trial court should have applied Boyd. Recognizing that 0 & M's status as an independent contractor and AEC's vicarious liability for 0 & M's negli-genee were the central factual and legal issues at trial, the Court of Civil Appeals found that failure to properly instruct the jury very probably affected the result and reversed the judgment entered on the jury verdict. The Court of Civil Appeals did not consider the issues raised and argued by plaintiffs concerning the status of the relationship between AEC and 0 & M and the insufficiency of the evidence to allow an intervening cause instruction. We granted AEC's petition for writ of certiorari.
II. AEC did not owe plaintiffs a non-delegable duty imposed either by the law of easements or because AEC was engaged in an inherently dangerous activity.
A. The independent contractor rule.
{12 An independent contractor is one who agrees to perform a certain service without the control, supervision, or direction of his employer in all matters connected with the 'performance of the service except the result or product of the work.1 Generally, an employer is not liable for the negligent acts or omissions of an independent contractor committed in the course of performing the contracted service.2 This non-liability rule is based on the notion that since the employer has no right of control over the manner and method in which the service is performed, the employer is not answerable for an injury resulting from the manner in which the independent contractor carries out the details of the work.3
B. AEC, as the owner of an easement, did not owe a non-delegable duty to the plaintiffs.
113 The independent-contractor rule of non-liability has been eroded by well-recognized exceptions. One exception is that an employer who performs work through an independent contractor is liable for damages to third persons caused by the negligence of the independent contractor where the employer owes a non-delegable contractual or defined legal duty to the injured party.4 In cases of non-delegable duty, an employer may be held liable for the negligence of an independent contractor although the employer has exercised reasonable care in all endeavors. In effect, "non-delegable duty" cases become ones of vicarious lability.5
14 Duty depends upon the relationship between the parties and the general risks involved in the undertaking; and, whether a defendant stands in such relationship that the law will impose upon the de[456]*456fendant an obligation to the plaintiff is a question of the law.6 Whether a duty is non-delegable is also a matter of law.7 Questions of law are reviewable by a de movo standard and the appellate courts have plenary, independent, and non-deferential authority to re-examine the legal rulings.8
115 The parties agree that AEC, as owner of the easement, had a non-delegable duty in using and maintaining its easement to avoid negligently injurying the servient estate. However, plaintiffs contend that the law of easement extends this non-delegable duty to all landowners who suffer harm as a result of a breach of the duty not just to the holder of the servient estate.9 The Court of Civil Appeals agreed.
116 We disagree. According to our extant jurisprudence, easement law imposes a non-delegable duty on the dominant tenant to use the easement in a manner so as to not damage or injure the servient estate.10 These cases teach that the non-delegable nature of the duty, while imposed by law, arises from the relationship between the dominant and servient tenants created by the easement grant. The cases do not suggest that the law extends the non-delegable nature of the duty to third parties who have no interest in the servient estate.
1 17 The early case of Minnetonka Oil Co. v. Haviland, supra, determined that the defendant oil company, by reason of an oil and gas lease, owed a duty to the plaintiff landowner to drill an oil well without doing any unnecessary damage to the plaintiff's property. The court reasoned that because the work arose out of the lease between the plaintiff and the defendant, the defendant was liable for the negligent performance of the work without regard to the means by which it undertook to perform the work. Concluding that the oil company could not escape lability by delegating its duty owed the landowner, Minnetonka said that the landowner stood "in an entirely different relation to the defendant as to their rights and its duty in the premises from a third person who was a stranger to the contract [lease] under which the work was done." 11
118 Shell Pipe Line Corp. v. Curiis, supra, determined that under the grant of the easement, the defendant oil company owed a duty imposed by law to use its dominant estate so as not to injure or damage the plaintiff. Concluding that the oil company could not escape liability by delegating its duty owed the owner of the servient estate, Shell Pipe Lime explained that the "duty arose out of the contract providing for the right of way ... [but] the law and not the contract imposed this duty upon defendant." 12
[457]*457119 Cities Service Gas Company v. Christion, supra, also arose out of a pipeline easement. In that case, the injured party leased the land to pasture cattle and the defendant had a pipeline easement across the same land. Cities Service Gas again determined that the law imposed a non-delegable duty "upon the holder of a dominant estate to so use the property as not to injure or damage the servient estate."13
T20 The Court of Civil Appeals conceded that most of the cases discussing non-delega-ble duty in the context of easements were actions brought by holders of the servient estate. However, the Court of Civil Appeals found it to be significant that these cases do not expressly limit application of the "non-delegable duty" rule to damages suffered by holders of the servient estate. The Court of Civil Appeals then referred to Oklahoma Ry. Co. v. Boyd, supra, for the proposition that the non-delegable duty arising from the grant of an easement extends to all third parties.
121 The reliance by the Court of Civil Appeals on Boyd is misplaced because the non-delegable nature of the duty recognized in Boyd did not arise from a relationship created by an easement grant.14 Rather, the non-delegable duty in Boyd rested on the nature of the activity, i.e., interference with the natural flow of water. In Boyd, the railway owned a right of way and embankment along the right of way that crossed the North Canadian River. The embankment had three openings for the passage of water and was constructed, so flood water could run over the top of the embankment. The railway permitted Oklahoma City to use the right of way and embankment for a diversion dam in connection with the city's water system and reservoirs. The height of the embankment was raised and a single opening was left in it for the passage of water. A heavy rainfall resulted in a volume of flood water too great for the single passageway. The flood water could not go over the elevated embankment and it backed up onto plaintiff Boyd's property. The plaintiff sued the railway and the city for interfering with the natural flow of water. Boyd determined that when the railway first constructed its embankment across the North Canadian River, it owed the adjoining landowners and other third persons similarly situated a non-delega-ble duty not to obstruct the flow of water in the stream so as to cause them damage.15 While defined as a non-delegable duty, the duty imposed in Boyd rested on the interference with the natural flow of water and not on the relationship created by an easement.16
122 In summary, this jurisdiction has not extended the non-delegable duty of care owed by the dominant tenant of an easement to the servient tenant to all other third parties. All cases discussing the non-delegable duty imposed upon the dominant tenant were actions brought by holders of the servient estate. Language in these cases clearly suggests that the non-delegable duty is limited to the holders of the servient estate. Interpreting Boyd in the manner suggested by plaintiffs would create a legal anomaly where a fee owner may delegate duties owed to adjoining landowners and others but an easement owner may not delegate such duties.17 Accordingly, we hold, under [458]*458the facts and cireumstances in this case, AEC, as an easement holder, did not owe a non-delegable duty to the plaintiffs.
C. AEC was not engaged in an inherently dangerous activity that precluded it from delegating its duty of care to O & M.
123 As an alternative argument, plaintiffs argue that AEC engaged in a category of activity that can be described as inherently dangerous and accordingly it may not avoid liability by delegating the work to an independent contractor. a
124 Inherently dangerous activity is another recognized exception to the independent contractor rule.18 Inherently dangerous activity includes work that is obviously dangerous and work which in the ordinary course of events will cause injury to others if certain precautions are not taken.19
125 Companies engaged in transmitting electricity are engaged in a business that is inherently dangerous.20 An electric transmission company, in using an easement or right of way for its poles, wires, and appliances, must use that degree of care, caution and cireumspection in keeping with the dangerous character of its business.21 As a distributor of electricity, AEC has a duty to anticipate and guard against events which may reasonably be expected to occur because of the inherently dangerous nature of the industry.22 AEC cannot avoid liability for breach of this duty by delegating it to an independent contractor.23
126 However, an employer engaged in an inherently dangerous activity is liable only for the risks inherent in the activity itself, which the employer should contemplate at the time of its contract.24 The employer is not liable when the contractor creates a new risk, not inherent in the work itself and not reasonably contemplated by the employer.25
¶27 In this case, AEC hired O0 & M to replace utility poles in its electricity distribution system that had been de-energized for some two years. While replacing the utility poles, a fire ignited under a large digger truck owned by O & M after it had been driven over rough terrain. Although the cause of the fire is unknown, it is undisputed that the electricity transmitting wires were not related to the cause or spread of the fire. Under these facts, the alleged negligence of O & M is not related to a risk inherent in the normal and usual manner of doing the work. Rather, the alleged negligence may be properly viewed as collateral negligence.26 Ac[459]*459cordingly, we hold, under the facts and circumstances in this case, AEC did not owe a non-delegable duty arising from an inherently dangerous activity.
III. The trial court correctly allowed the jury to decide whether an independent-contractor relationship existed between AEC and O & M.
128 Plaintiffs asserted in their brief in chief that the trial court should have ruled as a matter of law that 0 & M was an employee or agent of AEC and the court erred when it allowed the jury to consider the nature of the relationship between the parties Because the Court of Civil Appeals viewed the "non-delegable duty" issue as dispositive of the appeal, the court did not address this proposition of error. Under the directive of Rule 1.180(b), we address the issue.27
€29 Whether a person is considered an employee or an independent contractor depends upon the facts peculiar to each case.28 The decisive test for determining whether one is an employee or an independent contractor is the right to control which the employer is entitled to exercise over the physical details of the work.29 Where the evidence is conflicting or where reasonable people may differ in conclusions therefrom, the issue is one of fact for the jury.30
€ 30 At trial both parties submitted considerable evidence on the issue. We have examined the record and find the evidence concerning the status of the relationship is in substantial dispute. Accordingly, the question of the-legal relationship between AEC and 0 & M is not one that could be resolved as a question of law. The trial court properly submitted the issue as one of fact for determination by the jury.
IV. The evidence produced at trial did not support an instruction on independent, intervening cause.
131 The Freedom Volunteer Fire Department responded to the call from the AEC dispatcher. At the time they arrived, the fire involved approximately one acre of ground. Before the fire could be totally extinguished,31 the wind speed increased and the fire escaped the firebreaks and spread rapidly across the grasslands.
132 At trial, AEC requested the court to instruct on intervening cause and provided the court instruction No. 9.8 of the Oklahoma Uniform Jury Instructions, Civil, the instruction on intervening cause. The court included this instruction in the instructions given to the jury. In their brief in chief, plaintiffs contended that the evidence produced at trial did not warrant the submission of this instruction to the jury. Because the Court of Civil Appeals viewed the "non-delegable duty" issue as dispositive of the appeal, that court did not address this proposition of error. Under the directive of Rule 1.180(b), we address the issue.
133 The requirements for the proper application of instruction No. 9.8 are set out in Thompson v. Presbyterian Hospital, Inc., 1982 OK 87, ¶ 15, 652 P.2d 260, 264:
The intervening factor which will break the causal nexus between the defendant's negligence and the resulting injury is called the "supervening" cause. A true supervening cause that will operate effectively to insulate the original actor from liability must meet a three-prong test. It must be (1) independent of the original act, (2) adequate of itself to bring about the result and (3) one whose occurrence was not reasonably foreseeable. Unless these character[460]*460istics are met, the chain of causation which extends from the original act to the injury is not broken. Whenever the causal factor under examination qualifies as one of supervening quality, the original negligence may be said to undergo a legal metamorphosis into a remote cause or "mere condition".
134 In submitting the instruction to the jury, it is not clear whether the trial court considered the mercurial nature of the winds or the alleged negligence of the Freedom Fire Department as an intervening act. However, neither of these factors was sufficient to interrupt or break the causal connection between O & M's act and plaintiffs' injuries. Neither satisfied any of the conditions of the three-prong test set forth in Thompson. First, the fire was able to escape the firebreaks and spread to the grasslands as a result of unextinguished embers blowing out of a tree. Accordingly, it cannot be said that the spread of the fire derived from a source independent of O & M's act. Second, neither the wind nor the alleged negligence of the firefighters was adequate by itself, separated from O & M's act, to bring about the fire. Third, the fact that variable weather conditions, including strong winds, or the negligence of others might intervene to exacerbate the severity of a fire is clearly foreseeable.32
§35 The evidence presented at trial was wholly insufficient to support the giving of an instruction on intervening cause. It is error on the part of the trial judge to submit an issue not supported by competent evidence to the jury.33 However, a jury verdict will not be disturbed because of error in instructing the jury unless the error was prejudicial to the complaining party.34 The standard of review of a challenged instruction is whether there is a probability that the jurors were misled and thereby reached a different result than they would have reached but for the error.35
¶36 The jury entered a general verdict in favor of AEC and against the plaintiffs. The challenged instruction interjected intervening cause as a central issue in the case. It provided AEC with a complete defense which was not available to it under the evidence. It is almost axiomatic that to submit an issue unsupported by competent evidence to the jury would be prejudicial error on the part of the trial court.36 We find there is a probability that the jurors were misled and thereby reached a different result than would have been reached but for the erroneous instruction. Accordingly, this case must be reversed and remanded to the district court.
T37 OPINION OF THE COURT OF CIVIL APPEALS, DIVISION I, VACATED; JUDGMENT OF THE TRIAL COURT REVERSED AND CAUSE REMANDED FOR FURTHER PROCEEDINGS CONSISTENT WITH THIS OPINION.
T38 SUMMERS, CJ., and HODGES, LAVENDER, WATT, and WINCHESTER, JJ., concur.
{39 KAUGER, J., concurs in part and dissents in part.
{40 HARGRAVE, V.C.J., and OPALA, J., dissent.