*290 DeNNY, J.

The appellant assigns as error the ruling of the court below in sustaining the defendant’s motion for judgment as of nonsuit. She insists (1) that the case should have been submitted to the jury under the doctrine of res ipsa loquitur, and (2) if the doctrine of res ipsa loquitur does not apply, then the case should have been submitted to the jury on the ground that defendant was negligent in permitting the poplar tree to exist within the reach of its wires.

The rule with respect to the doctrine of res ipsa loquitur, as laid down in Scott v. The London Docks Co., 159 Eng. Rep. 665, has been quoted with approval by this Court in many of our decisions as follows: “There must be reasonable evidence of negligence, but where the thing is shown to be under the management of the defendant or his servants, and the accident is such as in the ordinary course of things does not happen if those who have the management use proper care, it affords reasonable evidence, in the absence of explanation by the defendant, that the accident arose from want of care.” Saunders v. R. R., 185 N.C. 289, 117 S.E. 4, 29 A.L.R. 1258; Etheridge v. Etheridge, 222 N.C. 616, 24 S.E. 2d 477; Boone v. Matheny, 224 N.C. 250, 29 S.E. 2d 687; Wyrick v. Ballard, 224 N.C. 301, 29 S.E. 2d 900; Edwards v. Cross, 233 N.C. 354, 64 S.E. 2d 6; Nance v. Hitch, 238 N.C. 1, 76 S.E. 2d 461, 41 A.L.R. 2d 318; 38 Am. Jur., Negligence, section 295, page 989, et seq.

The doctrine of res ipsa loquitur is merely a mode of proof and when applicable it is sufficient to carry the case to the jury on the issue of negligence. However, the burden of proof on such issue remains upon the plaintiff. Pendergraft v. Royster, 203 N.C. 384, 166 S.E. 285; Young v. Anchor Co., 239 N.C. 288, 79 S.E. 2d 785.

This Court, in discussing the doctrine of res ipsa loquitur in the case of Springs v. Doll, 197 N.C. 240, 148 S.E. 251, pointed out that “The principle does not apply: (1) when all the facts causing the accident are known and testified to by the witnesses at the trial, Baldwin v. Smitherman, 171 N.C. 772, 88 S.E. 854; Orr v. Rumbough, 172 N.C. 754, 90 S.E. 911; Enloe v. R. R., 179 N.C. 83, 101 S.E. 556; (2) where more than one inference can be drawn from the evidence as to the cause of the injury, Lamb v. Boyles, 192 N.C. 542, 135 S.E. 464; (3) where the existence of negligent default is not the more reasonable probability, and where the proof of the occurrence without more, leaves the matter resting only in conjecture, Dail v. Taylor, 151 N.C. 284, 66 S.E. 135; (4) where it appears that the accident was due to a cause beyond the control of the defendant, such as the act of God or the wrongful or tortious act of a stranger, Heffter v. Northern States Power Co., 217 N.W. 102 . . .; (5) when the instrumentality causing the injury is not under the exclusive control or management of the defendant, Saunders v. R. R., 185 N.C. 289, 117 S.E. 4; (6) where the injury results from accident as defined and contemplated by law.” Smith v. McClung, *291 201 N.C. 648, 161 S.E. 91; Taylor v. Bd. of Education, 206 N.C. 263, 173 S.E. 608; Etheridge v. Etheridge, supra.

In the last cited case it is said the doctrine of res ipsa loquitur “does not apply where the evidence discloses that the injury might have occurred by reason of the concurrent negligence of two or more persons, or that the accident might have happened as a result of one or more causes, or where the facts will permit an inference that it was due to a cause other than defendant’s negligence as reasonably as that it was due to the negligence of the defendant, or where the supervening cause is disclosed as a positive fact — and skidding, Springs v. Doll, 197 N.C. 240, 148 S.E. 251, Anno. 64 A.L.R. 261, or a puncture or blowout, Clodfelter v. Wells, 212 N.C. 823, 195 S.E. 11; Giddings v. Honan, 79 A.L.R. 1215; Ingle v. Cassady, 208 N.C. 497, 181 S.E. 562, is such fact. Blash-field, supra (9, part 2), sec. 6046. When the supervening cause appears as an affirmative fact it never applies. No inference of negligence then arises from the fact of accident or injury.” Edwards v. Cross, supra; Mills v. Moore, 219 N.C. 25, 12 S.E. 2d 661; Austin v. R. R., 197 N.C. 319, 148 S.E. 446.

In the trial below the evidence offered in behalf of the plaintiff was to the effect that her injury was caused by the action of Jesse Moore-field in cutting down a tall poplar tree about 75 feet in height and 22 inches in diameter at the stump, which fell across the defendant’s power line and broke or otherwise damaged the wires leading through the Moorefield farm to the McKinney house where the plaintiff lived. This evidence makes the doctrine of res ipsa loquitur inapplicable. Springs v. Doll, supra.

The cases of Turner v. Power Co., 154 N.C. 131, 69 S.E. 767, 32 L.R.A. (N.S.) 848, and McAllister v. Pryor, 187 N.C. 832, 123 S.E. 92, 34 A.L.R. 25, and similar cases cited and relied upon by the appellant, are not controlling on the facts revealed by this record.

. On the plaintiff’s second contention, she insists that the defendant could have foreseen that a tree 22 inches in diameter and 75 feet high, near its power line, would some day fall, either from the woodsman’s axe or from natural causes and that it would fall on its power line and likely cause damage to some person.

This Court declared in Helms v. Power Co., 192 N.C. 784, 136 S.E. 9, that: “Electric companies are required to use reasonable care in the construction and maintenance, of their lines and apparatus. The degree of care which will satisfy this requirement varies, of course, with the circumstances, but it must always be commensurate with the dangers involved, and where the wires maintained by a company are designed to carry a strong and powerful current of electricity, the law imposes upon the company the duty of exercising the utmost care and prudence consistent with the practical operation of its business to avoid injury *292 to those likely to come in contact with the wires.” Ellis v. Power Co., 193 N.C. 357, 137 S.E. 163; Small v. Utilities Co., 200 N.C. 719, 158 S.E. 385; Alford v. Washington, 238 N.C. 694, 78 S.E. 2d 915.

We know of no law or decision, however, in this jurisdiction that requires a power company to cut down and remove every tree on or near its right of way, regardless of whether such tree is sound or decayed, which if cut down might possibly fall across its line. On the contrary, the right of way agreement which the plaintiff contends is applicable to the line under consideration only provides for the power company “to cut away all trees and other obstructions that might in any way endanger the proper maintenance and operation of same.”

Certainly this agreement does not impose upon the power company the duty to cut down a sound tree near its line, which in no way interferes with the operation or maintenance thereof, simply because it is possible that at some future time the owner of the land, or his agent or a stranger, might cut down such tree and cause it to fall across its line. This is purely speculative.

In the case of Deese v. Light Co., 234 N.C. 558, 67 S.E. 2d 751, the plaintiff’s intestate, a staff sergeant in the United States Army, was home on furlough visiting .his father. The defendant light company, by authority of a written easement, maintained across plaintiff’s land an uninsulated tap line 18 feet or more above the ground, which line was energized with approximately 2300 volts of electric current. Plaintiff’s intestate felled a tree across defendant’s line and while attempting to disengage the tree from the line, he came in contact, directly or indirectly, with the line and was electrocuted. This Court sustained a judgment as of nonsuit on the ground that the action of plaintiff’s intestate in cutting down a tree across the defendant’s line did not constitute actionable negligence on the part of the defendant.

A power company is not required to anticipate negligence on the part of others. Alford v. Washington, supra; Cox v. Freight Lines, 236 N.C. 72, 72 S.E. 2d 25; Wood v. Telephone Co., 228 N.C. 605, 46 S.E. 2d 717; Montgomery v. Blades, 222 N.C. 463, 23 S.E. 2d 844.

In our opinion the plaintiff has failed to establish actionable negligence on the part of defendant, and we so hold. The judgment as of nonsuit is

Affirmed.