Abstract: Three cranes were lifting a section of steel roofing structure for an aircraft hanger. A 150-ton crane was lifting one end of the structure while two 50-ton cranes were lifting the opposite end. When the 150-ton crane began to list toward the load, the operator lowered his load to ground level. One of the 50-ton cranes then lowered its load. This caused the beam to break on the other 50-ton crane and the entire steel structure to fall, knocking Employee #1 from a stationary column to the ground. Employee #1, already injured, attempted to escape the falling load, but was struck by falling steel and killed. Employee #2 was also struck by the falling material and sustained injuries that required hospitalization. Subsequent investigation revealed that the position of the 150- ton crane was off by approximately 4 feet, causing the other crane to become overloaded.