Abstract: At about 9:30 a.m. on July 15, 1987, Employee #1, a pipe installer employed by CC&T Construction Co., Cockeysville, MD, and a coworker, were installing sections of 48 in. by 8 ft concrete storm drain pipe about 35 ft under I-270, north of 404 Watts Brook Pkwy., Rockville, MD. Both men were inside the tunnel. Another coworker was positioned outside the tunnel at the east end and was operating a winch that was used to pull the sections of pipe together. The pipe sections were positioned on 4 in. by 4 in. wooden skids. During the winching a section of pipe became stuck. Employee #1, who was positioned inside the stuck pipe, leaned outside of it to jack the pipe free. He said "O.K." to the second man in the tunnel. The winch operator thought the "O.K." was for him and started to winch the pipe. Employee #1 was caught between two pipes and was crushed to death. A comprehensive signal system between the worker and the winch operator was not used.