GW officials evacuated Munson, JBKO and Madison halls Sunday evening after an underground electric cable caught fire and caused at least two manhole covers to explode, said Bob Ludwig, assistant director of Media Relations. Power company officials did not know the exact location of the fire.

Munson and JBKO remained closed for the night. About 300 students were relocated to the GW Inn and the State Plaza and Doubletree hotels, said Nicki Ferramosca, a GW spokesperson. She said those residence halls were reopened at 8 a.m. Monday, and students returned to Madison Sunday night.

Those buildings are located on the blocks where explosions occurred, and electric lines that were affected by the fire are connected to the buildings, Ferramosca said.

Manhole covers exploded on I Street and because of the smoke they evacuated the residence halls for safety precautions, Ludwig said.

Potomac Electric Power Company spokesman Robert Dobkin said the electric company received a call from the fire board at about 6 p.m.

The incident began when one of the three 13,000 volt feeder cables running along I Street failed, but the circuit breaker for that cable failed to shut off power to the faulty cable, causing it to catch fire and damage two other cables in the same duct, he said.

Circuit breakers for the other two cables functioned properly, Dobkin said. We have multiple protections in the system, he said. That’s the first line, the breaker in the substation (on I Street),.

The damaged feeder cable also runs along 22nd Street and caused a fault to develop there, Dobkin said.

Students said they saw a manhole cover explode at the corner of 22nd and G streets in front of Funger Hall. It got really dark over here all of a sudden, said junior Clark Rehme, who was walking along 22nd Street to Francis Scott Key Hall from Gelman library. You didn’t even see the manhole cover lift up, he said.

Rehme said smoke and flames shot out of the manhole at about 6:30 p.m.

Ludwig said PEPCO worked through the night to repair the underground electric lines. If you walk along I Street you can see what looks like burnt cable, what they replaced, he said.

Dobkin said the first cable that caught fire still needs to be replaced, and workers are still repairing the line at the corner of 22nd and G streets.

The damage most likely occurred because of wear on the cables, which are subject to friction and extreme temperatures that may cause the insulation to erode, Dobkin said.

We’re trying to figure out why the breaker went out, he said. From time to time, stuff breaks down.

All power was restored to affected buildings Monday, Dobkin said, except for the Health and Wellness Center construction site at 2301 G Street.

We’re sorry, he said. We know what finals week is like.

-Rich Murphy and Ashley M. Heher contributed to this report.