Abstract: At about 2:30 p.m. on February 24, 1984, Employee #1 was installing an angle iron frame for a rooftop exhaust support. The built-up roof was already in place, and he was working from inside the building, using a sheet metal air duct as a work platform. Employee #1 was standing on a 50-in.-long section of duct (the end piece of a horizontal run), which cantilevered approximately 47.5 in. from a support hanger. The only support for the cantilever duct section was a "pocket lock" joint that connected the duct sections to the hanger, which was located about 2.5 in. in front of the joint. The added weight from Employee #1 caused the pocket lock joint to separate, and the duct fell to a concrete floor. Employee #1 also fell, reportedly landing on his head and side. He was taken to Moses Cone Hospital in Greensboro, NC; the hospital reported his death to job site officials at about 5:00 p.m. the same day. Employee #1 was not wearing personal fall protection equipment.