About 15,000 Utah Power & Light customers in the Salt Lake Valley were without power for about 60 minutes Friday night after a circuit breaker on a substation exploded, a company official said.

UP&L spokesman Gary Clayton said a circuit breaker blew at the southeast substation on 11th East and 24th South.He said some customers saw only flickering lights when the breaker blew about 8:40 p.m., while others were left in the dark until power was restored one hour later.