Inspection Detail

Inspection: 303733646 - Structural Systems Technology Inc

Inspection Information - Office: Omaha Area Office

Investigation Summary

On September 24, 2002, Employees #1, #2, #3, and #4 were subcontracted to replace diagonal braces and reinforce certain areas of a 1,965 ft tall KDUH-TV tower for an upgrade to high definition television. Employee #1 worked in the area of section number 10 and Employee #2 worked in the area of sections number 47 and number 48, at the connection location of the tower legs. According to the assembly details, 10 diagonal braces were to be replaced in section number 47. The existing braces were found to be unbolted. At the time of the tower collapse, there was a separation of the tower legs at their flange connections between sections number 61 and number 62, which allowed sections number 48 through number 61 to collapse to the southwest of the tower base. Another separation occurred between sections number 47 and number 48, which caused sections number through section number 47 to collapse. After the tower collapse, the metal members were bent and twisted, and the fallen tower was lying across the field. Employees #1 and #2 were killed in the collapse. Employees #3 and #4, roofers repairing the roof of the transmitting building, were injured when they were struck by falling guy wires. Both sustained injuries that required hospitalization. During the subsequent accident investigation, Section number 48 was lifted out of the ground, and open holes were observed on the gussets where bolts either were removed or had been broken in the collapse of the structure.

Keywords: COLLAPSE, FALL, STRUCK BY, TELECOM WORK, UNSECURED, TOWER, FRACTURE, COMMUNICATION TOWER, CONSTRUCTION, FALLING OBJECT