Opinion by
Mr. Justice Kephart,This was an action brought under the Federal Employers Liability Act of 1908 by the appellee to recover for the death of her husband. The sole question for determination, as stated by the appellant, is, does the testimony in the case show such a failure on the part of the company to exercise a duty owing to the defendant at the time of the accident, as would overcome the risk assumed by him, and thus bring the case within the federal statute; or, stated in another form, was the negligent act complained of, likely to happen, or so obvious, that the decedent must have known, or, as a reasonably careful person, should have known of it, and anticipated what happened, so that the court might say, as a matter of law, it was among the risks assumed, and, for that reason, his representative could not recover? By section 1 of the Employers Liability Act, a right of action is conferred on those injured engaged in interstate service by reason of negligence (1) of the employer, agents, employees, or fellow servants, (2) in providing insufficient or defective appliances. Injuries not due to negligence are excluded. *219By section 3, contributory negligence of the injured person is not a bar, but when present (except where the injury is due to the violation of an act of Congress enacted for the safety of employees) the doctrine of comparative negligence is enforced. By section 4, an employee does not assume the risk of his employment, where the injury is due to the violation of a statute enacted for the safety of employees. “It seems to us that section 4, in eliminating the defense of assumption of risk in the cases indicated, quite plainly evidences the legislative intent that in all other cases such assumption shall have its former effect as a complete bar to the action”: Seaboard Air Line v. Horton, 233 U. S. 492, 503; Jacobs v. Southern Ry., 241 U. S. 229, 235; Boldt v. Penna. R. R., 245 U. S. 441, 445. Except, then, as to the injuries resulting from the violation of statutes, the common law doctrine of assumption of risk still remains as a complete defense in an action under this statute, and is applicable to a case such as presented by the facts now before us. The employee assumes, as a risk of his employment, such dangers as are normally and necessarily incident to his occupation, and a workman of mature years, is taken to assume them whether he is aware of their existence or not ; but risks of another sort, not naturally incident to the occupation, may arise out of the failure of the employer to exercise due care. They are the unusual, extraordinary and unexpected acts, and the employee is not to be treated as assuming such risks until he becomes aware of their existence, unless the act or risk is so obvious that an ordinarily prudent person would have observed and appreciated them: Seaboard Air Line v. Horton, supra; Jacobs v. Southern Ry., supra; Boldt v. P. R. R., supra; C. & O. Ry. Co. v. De Atley, 241 U. S. 310, 315; Erie R. Co. v. Purucker, 244 U. S. 320; C. & O. Ry. Co. v. Proffitt, 241 U. S. 462, 468. It is only in a clear case that the question of the assumption of a risk is one of law for the court, and where there is doubt as to the facts, or as to inference to be drawn from them, it becomes a question *220for the jury: Falyk v. Penna. R. R. Co., 256 Pa. 397, and cases there cited. The burden of proof as to the assumption of risk is on the defendant: Kanawha & Mich. Ry. Co. v. Kerse, 239 U. S. 576, 581.
The court below correctly instructed the jury both as to the law of contributory negligence and assumption of risk, and after a thorough review of the evidence we are not persuaded the risk was so obvious as to bring it within the class of cases where it becomes the duty of the court to declare it so as a matter of law. We agree that ordinarily the servant assumes the risks incident to the negligent acts of the officers, agents and fellow employees of the master: Boldt v. P. R. R. Co., supra; but he does not assume the risks of unusual and extraordinary acts of negligence.
In the present case, the deceased was employed as a repairman in the interlocking department, and, while engaged in oiling a switch, was run over by a “helper” engine moving backwards. He was thus employed for three or four years, and his duties required his presence on the tracks at various points. He was killed in the yards, where there are three tracks, two main and one siding. A train had just moved to the east, and was assisted over the grade by the “helper.” This engine returned backwards, as was its custom, to occupy the siding west of the bridge so as to be in a position to assist the next train moving east. In this movement it must use the cross-over switch where the deceased was working. From his position, he could have seen, if standing, a distance of three or four hundred feet to the east; but when stooping, as this work required, he could not see beyond the end of the bridge; the girders were from four to five feet in height, completely obstructing Ms view. There was a stop signal against the engine, as it made its return trip, and this was not released until the engine was close to the bridge. It clearly appeared that it was the custom to ring the bell as a warning, while moving the engine backwards, and the defendant offered evidence *221to show that it had, for a distance of two or three hundred feet, performed this duty. This evidence was flatly contradicted and raised the important question of fact on which the case was submitted to the jury.
The conditions surrounding his work were unusual. To properly perform it, he must be in a stooping position, and was thus prevented, by the girders of the bridge, from seeing any safe distance, as the track curved sharply just before the approach to the eastern end of the bridge. Since the work required some little time, he could not stand erect every few minutes to observe approaching trains, and had he done so he would have seen nothing but the signal set against the engine. In the course of his work, situated as he was, he must depend on the usual, ordinary and customary signal given workmen thus employed, and the jury was warranted in finding he had a right to expect nothing unusual would happen. He was not, however, relieved of the obligation of using every precaution imposed on a prudent man; but, in the performance of this obligation, he must be judged by the character of the work engaged in, the immediate surroundings and the necessities the work entailed in its performance. The engineer, in returning from the top of the grade to the siding below, always gave the customary signal. He was in the yard limits, and knew that men were likely to be engaged at this particular place, made extra hazardous by the location of the cross-over with reference to the curve of the track and the obstructions along the track preventing a view. His failure to give warning at this time, as found by the jury, was an unusual and unexpected act, not to be ordinarily foreseen.
The case was carefully tried and we see no' reason why the judgment should be disturbed. The assignments are overruled and the judgment is affirmed.