Abstract: At about 6:00 a.m. on March 9, 1989, Employee #1 and a coworker were removing an approximately 2,500 lb roof panel from an HVAC unit using a 10 ton overhead traveling crane and two sling chains. Employee #1 had lifted the 5 to 6 ft high roof off the unit with the crane and was lowering it over the side of the building for repairs. As the roof was being lowered, the far edge caught on a coil pipe that stuck out 5 in. from the side wall. The roof bounced, causing the safety latch on the crane hook to fail. The chain came loose and the roof fell, striking Employee #1 on the side of his face and on his left hand, and fracturing his left hip and leg. He was wearing a hard hat. He was hospitalized for his injuries.