The lines came down about 3:30 p.m. No injuries were reported.
Southern California Edison responded to the 25200 block of Filaree Avenue and shut the power off from Kitching Street to Filaree Street and Perris Boulevard to Gentrian Avenue, officials said.
A SoCal Edison spokesman said 2,500 customers were without power due to the downed power lines. By 6 p.m., about 200 homes were still without power. Officials said they hoped to have power back to the remaining customers by early morning.
Edison suspects the cause of the downed lines may have been a helium-filled foil balloon that started the chain reaction.