The outby mechanic was doing his permissibility on LC #8, when he went to location he found a roof on top of the 7200 cable. He went & got foreman & knocked power. Area approx. 100' long from STA #8302. Area was bolted with 4.5 1 piece bolt. The area has been cribbed off and 7200 re-routed. This fall was in South Main Section. The height at the fall was approx 5'.