A worker set up a 10 ft. extension ladder on a basement floor over an elevator pit. He used an electrical conduit on the floor as a base. The horizontal span over the pit was six feet, resulting in a ladder inclination of four vertical to three horizontal. It is believed that the worker reached to one side, causing the ladder to rotate at the base and slip out. The worker fell head-down into the pit and later died from the head injuries he sustained.

When in use, a portable single or extension ladder shall be so placed that the horizontal distance from its base to its vertical plane of support shall be approximately one-fourth of the ladder length between supports. Any portable single or extension ladder shall be equipped with a non-slip type base, or shall be held, tied or otherwise secured to prevent slipping.