BART stations across the Bay were closed since 8 a.m. to approximately 12:30 p.m. Sunday "due to a systemwide computer problem."
SFMTA was providing bus service between downtown San Francisco and Daly City on line 14R from Mission St. Busses are also providing special service between Daly City, Balboa Park, and Glen Park stations.
At around noon, service was restored between Montgomery station in San Francisco and all East Bay stations.
After service was restored, BART tweeted that due to maintenance, Downtown San Francisco trains will be using only one track between Powell St and 16th St/Mission. The agency advised the public to expect delays.
No further details have been released.