An electric equipment explosion shook a 19-story office building in downtown Los Angeles, sending two people to the hospital and leaving a dozen surrounding buildings without power Friday.

The blast Thursday night in the downtown business district home to offices, bars and restaurants also caused a momentary power outage at the nearby Staples Center, where a Shania Twain concert was underway, arena officials said.

Smoke billowed into the street, but a fire that broke out was quickly extinguished as more than 160 firefighters rushed to the scene, according to the Los Angeles Fire Department.

The explosion broke some pipes, flooded part of the building's basement and rendered the fire-safety system inoperable, but the structure itself appeared to be sound, fire department spokesman Brian Humphrey said.

A woman with head pain and a man with back pain were taken to hospitals, while two others checked at the scene declined treatment, Humphrey said.

The blast caused extensive damage to an industrial power station, cutting electricity to 12 nearby buildings that were still in the dark, the Department of Water and Power said in a statement.

Crews believe they can restore power to all the buildings Friday except the one where the explosion occurred, agency spokeswoman Terry Schneider said.