SEATTLE -- An explosion and fire at a Seattle City Light substation snarled traffic near the Seattle Center and apaprently caused a power outage Tuesday.

Drivers reported hearing an explosion just before 10 a.m. near the substation at Broad and Harrison streets.

KIRO 7 Eyewitness News crews found smoke and steam rising from a vault. Streets in the area were blocked off, and the force of the blast blew a manhole cover to pieces.

At about the same time, power went out for about 4,000 City Light customers in the city's Magnolia neighborhood.

The area affect was from West Fort Street to West Galer Street and from 15th Avenue West to Puget Sound. Power was restored Tuesday afternoon.

No one was hurt. City Light couldn't immediately say whether the two incidents are related.