BART said that normal two-track service is resuming after there were major delays early Tuesday morning due to track maintenance, including a system-wide delay of 10 minutes in all directions.
The transit agency briefly had to run trains on only a single track through the Transbay Tube due to an electrical issue, but the problem was resolved.
No trains were stranded in the underwater tube connecting Oakland to San Francisco, but some trains had to turn around to help keep service moving around the system while crews evaluated the problem.
As of shortly after 6:30 a.m., normal service had resumed, according to BART.