A series of electrical explosions knocked out power to part of downtown Des Moines, including the Federal Building, early this morning.

Three explosions in the Court Avenue District blew manhole covers on the street into the air. Witnesses reported flames from the open manholes shot up to 30 feet above street level.

“Around 2:45 this morning we had an underground cable that faulted,” says Tina Potthoff, a spokeswoman for MidAmerican Energy. “We currently have crews on site to make those repairs.”

Power should be restored to most businesses in the area by 10 a.m.

“But there will be some businesses that will be out all day — just a handful, if you will — while we make repairs and replace that electrical system that was damaged,” Potthoff says.

Some witnesses told police they smelled gas, but Potthoff says the explosions were not caused by a natural gas leak.

“We’ve hadcrews out there this morning since the incident happened taking readings in the area and we’ve detected no natural gas in the area,” Potthoff says. “We did not make any evacuations and portions of the road are blocked off as we make repairs, but it is strictly electrical.”

The Federal Building is closed to the public all day, due to the power outage. Both of Iowa’s U.S. senators have offices in the building, although both senators are in Washington, D.C. for senate votes this week. Several federal agencies have staff working out of the Neal Smith Federal Building in Des Moines as well.