after stating the facts, delivered the opinion of the court.
1 The nonsuit was properly overruled. It was the duty of defendant to provide reasonably safe passageways and approaches in its mine to and from the place where plaintiff was at wort, and to exercise ordinary care in keeping them in a reasonably safe condition. Linden v. Anchor Min. Co., 20 Utah 134, 58 Pac. 355; Buzzell v. Mfg. Co., 48 Maine 113, 77 Am. Dec. 212; 1 Shearman & Redfield on Negligence, 194.
2 It appears from the record that the lagging which gave way and caused the injuiy to plaintiff covered a space of six feet only, and was composed of planks of the width and thickness used in mines generally for like purposes. Plaintiff had a right to presume, and to act upon the presumption, that the defendant had used ordinary care in the selection of the timber to make this platform or floor, and that it was safe and suitable for the purposes for which it was constructed. And it can not be held, as a matter of law, that when he came to this floor, on the night in question, with only his candle to light his course, he was guilty of negligence in walking, or, rather, in attempting to walk, across it; this being one of the purposes for which it was intended.
3 While it is a well-established rule of law that the servant assumes the risks, dangers, and hazards that are ordinarily incident to, and naturally arise out of, the employment in which he is engaged, yet he does not assume the unusual and extraordinary risks caused by the master’s negligence in failing to perform some duty imposed upon him by law, which'he owes to the servant, unless the risks and dangers ere-*538ated by such negligence are open and visible, or the servant has knowledge of them. Bailey, Master’s Liability to Servant, 151-155. In this case the shift boss, under whose direction the plank was placed across the timbers referred to, had every opportunity to inspect and observe the defective condition of the plank. He and the men under him had the handling and moving of it to the place where it was used, and therefore had a much better opportunity to discover its defective condition than the plaintiff; and there is not a scintilla of evidence that even suggests that the defective condition of the plank was known to plaintiff, or that it was so open and visible that he knew, or by the exercise of ordinary care would have known, of it.