EE was pulling rope through 8"" pipe which was attached to a 5"" hose. The end of the pipe 4.5' from edge. EE was near the face of a 15' drop. EE should've been tied off to prevent falling. EE wasn't. Rope broke & EE fell backwards & landed on feet & hurt left foot. EE had bruised hand w/minor cuts. Brought EE to ER, x-rays determined fractured heel. EE was wearing hard hat.