Nearly 2,000 customers were affected after an explosion caused a power outage Tuesday in Upland, according to Robert Villegas of Southern California Edison.
San Bernardino County Fire Department received a call of a transformer explosion at 8:38 p.m. in the 900 block of West Villa Serena, where they saw an underground transformer on fire.
Additional units were requested after more transformer fires sparked. The flames were doused and nearly an hour later, another large explosion from a power box was reported at El Mirador, west of Vista Grande.
The cause of the explosions are under investigation and officials did not provide an estimate on when power would be restored.