BART officials said there was an electrical fire at one of their substations which caused a loss of power on the tracks.
Service has resumed between El Cerrito del Norte and Richmond stations. They are still working to restore service between Del Norte and downtown Berkeley.
"I just want to assure the public that we're going to take a really close look at what happened with this and see if there are any improvements that can be made and look at the infrastructure and make sure that all the repairs are done," said BART Spokesperson James Allison.