While rigging down the tower light in the process of lowering down the light pole, the hoist gear got stuck. The operator called the mechanic to inspect the issue and he came and assess and could not rectify the issue therefore the mechanic went to his shop to look for barricade tape, LOTO gears in order to isolate the work area. During this time, the mechanic heard a loud bang. He then came out of the shop and noticed one employee (IP) laid down on the ground and noticed an injury on his head.