Inspection Detail

Inspection: 310093273 - Jc Metal Specialists, Inc.

Inspection Information - Office: Foster City District Office

Investigation Summary

One morning a journeyman concrete cutter working for a concrete sawing company had cut out three sections of 150-millimeter-thick wall into a total length of about 9 meters long by 4.6 meters high. Each of these concrete sections was secured onto the surrounding building facade with expansion bolts securing lengths of Unistrut construction material near the top edges of the sections. Having completed the work as specified by contract, he met with the owner of the structural metal manufacturing company that had contracted the work. They met at the work area, and the cutter turned that project over to the structural metal manufacturer. A supervisor for the structural metal manufacturer assigned two carpenters to prepare rigging for removing the concrete panels. Shortly before noon, a third carpenter came over to the wall and steadied a ladder for one of the first two carpenters, who climbed the ladder and removed two of the Unistrut securing straps from one of the three concrete panels. That carpenter discovered that one of the chains they were to use in the rigging was too short. Following a lunch break, the extra carpenter again assisted, standing on the outside of the building, next to the unsecured concrete wall section, while the carpenter who had removed the securing straps passed a length of chain from inside the building through window and door openings in the wall to the assisting worker. As the assisting worker took the chain, the wall became unstable and fell onto him, crushing him to death. The employer had not trained any of the three carpenters or their supervisor in demolition methods, and none of those employees had previous experience in the demolition of concrete walls or similar structures. (The concrete sawing firm had originally offered to provide for the demolition of the walls and removal of the debris, but the structural metal manufacturer declined the offer.)

Keywords: RIGGING, WALL, DEMOLITION, CRUSHED, UNTRAINED, UNSTABLE POSITION