Exceptions overruled. The plaintiff, an employee of the Cambridge water department, was, at the request of the defendant, investigating a flooding of the cellar of its store. Access to the cellar was by means of a trap door located upon the first floor. It was of metal and consisted of two leaves, each of which was about forty-four inches in length and nineteen inches in width and swung toward the other when closed. When opened each of the leaves swung up-. ward and was held open by a piece of wood one quarter of an inch thick and thirty to thirty-six inches long, each end of which rested on a leaf. The trap door, when the plaintiff arrived on the premises, was open with the stick holding the leaves apart. The leaves were not up perpendicularly but inclined a bit toward each other. They were in the same position at the time of the accident. While the plaintiff was ascending a short ladder which led to the trap door and when his shoulders were on a level with the first floor, the stick in some way became loosened and both leaves swung down, one of them hitting him upon the head. Eveiything connected with the situation was open and obvious. A warning by the defendant would not give the plaintiff more than he could learn at a glance. There was no error in directing a verdict for the defendant. Walker v. Benz Kid Co. 279 Mass. 533, 537-538. Williams v. United Men’s Shop, Inc. 317 Mass. 319, 321. Bloom v. Warshaw, 332 Mass. 14, 16-17.