One of the cars contained frozen meat and the other three contained wood products. No one was injured in the derailment.
Service has been restored on a BART line after crews worked through the night to repair tracks damaged by a derailed train.
BART removed three of four cars from an out-of-service train that derailed in Concord during the Friday evening commute, prompting buses and a shuttle train to stand in for normal train service between four stations on the Pittsburg/Bay Point line.
BART officials are saying that repairs to a damaged train, track and third rail following a derailment at the Concord BART station Friday evening are likely to continue through Saturday night.
The San Francisco Municipal Transit Agency is investigating the derailment of a Muni streetcar in front of the West Portal Station early Friday morning.
At least 30 people were injured when an Amtrak train that was traveling from Oakland to the Central Valley was struck by a big-rig Monday afternoon, Amtrak and local law enforcement officials said.
A new earthquake early-warning system installed by Bay Area Rapid Transit will detect earthquakes precious seconds before the ground starts shaking, allowing trains to be slowed down in an effort to prevent derailments.
At least seven people were taken to a hospital after an Amtrak train headed from the Bay Area to Chicago and carrying about 175 passengers hit a vehicle and derailed in southwest Nebraska, authorities said.
The investigation into what caused two train cars to derail outside the Concord station on Sunday morning is expected to take weeks or even months, a BART spokesman said Monday.
A BART train in Concord headed for San Francisco Sunday morning derailed, causing major delays on the Bay Point line in both directions.