Abstract: At approximately 7:30 a.m. on March 28, 1986, Employee #1 and coworkers were installing plywood siding at the northeast corner of an addition to a maintenance building. They were working on a tubular welded frame scaffold that was approximately 12 ft above ground. Employee #1 had been on the ground cutting the plywood and handing it up to a coworker who was on the scaffold to tack it in place. Employee #1, who was a heavyset man, decided to climb onto the scaffold to check measurements for accuracy. He climbed a ladder at the north end of the scaffold and proceeded toward the middle of the scaffold. When he got to the middle of the scaffold, one of the boards broke and he fell approximately 12 ft through the scaffold to the ground, landing on his back. He sustained several fractured ribs, various contusions and abrasions, and injured his back. Employee #1 was hospitalized. Failure to check the condition of all the scaffold boards prior to doing any work from this scaffold caused the fall.