Bay Area rail commuters were left without service Friday morning because of what operators called "major computer issues" that left hundreds of riders stranded in stalled trains.
As of 6 a.m., rail commuters were being told to find alternate forms of transportation as the Bay Area Rapid Transit system worked to repair the computer glitch.
BART spokesman Jim Allison told KGO-TV that the system-wide delays began shortly after midnight and resulted in between 500 and 1,000 passengers waiting onboard 19 nonmoving trains early Friday morning.
All passengers on the final Thursday night trains reached their destinations Friday morning, Allison said.
The issue was related to computer systems in central control not communicating properly with track switches.
In the lead up to the busy rush hours Friday, the union that represents train operators and other workers tweeted, "Computers still down, please find other means of transportation until further notice."
The systemwide delay was expected to cause major headaches for morning commuters who likely missed the public alerts. BART said on its website that there would be no service until further notice.
The service interruption comes as BART's two largest employee unions spar with management over a lingering contract dispute.
A new labor agreement between BART and its workers recently hit a snag after the Bay Area transit agency acknowledged it mistakenly left what it called a costly provision in the tentative contract, throwing the accord into doubt.
The San Francisco Bay Area was paralyzed twice this year by the strikes. The 104-mile rail system carries 400,000 passengers every weekday.
[Updated 7:20 a.m. PST, Nov. 22: BART announced shortly before 7:20 a.m. that the computer glitch had been fixed and that all trains were back in service. Still, the agency warned passengers to expect system-wide delays.]