Abstract: On June 13, 1994, Employee #1, a laborer for a plant construction company, was at a construction site helping to demolish a sidewalk. He and several coworkers were standing on a plank that spanned the sidewalk, using a jackhammer to break up the sidewalk directly in front of them, and moving steadily toward the back. Employee #1 took over the hammer while the operator went to get coffee for their break. At approximately 11:00 a.m., the sidewalk collapsed and Employee #1 fell in. He was taken to San Francisco General Hospital where he was treated for lacerations on his head, a gash on his stomach, bruises on his arms and legs, and internal bleeding.