BART trains rolling again after mysterious system-wide shutdown

SAN FRANCISCO (KGO) -- BART trains are rolling again, but Saturday morning the whole system came to a screeching halt for several hours, leaving riders out in the cold and looking for other transportation.

An announcement was broadcast in all BART stations: no trains were running. Not exactly the news BART riders wanted to hear, no trains running anywhere, not one.

RELATED: Full BART service restored after systemwide shutdown caused by computer problems

Breland Mosley was trying to get to school in Hayward.

"I have to be there at 10 am, I'm gonna be late," said Mosley.

The closure was first announced about 5:45 a.m. By nine o'clock, the system was running again but only on a limited basis. No trains were running between Daly City and SFO. That was a huge problem for Maria Legacion who works for Virgin Atlantic Airlines.

"Right now, we're waiting for a BART bus, that's going to take us to SFO, We've been waiting for an hour, very frustrating," said Legacion.

Several riders complained there weren't enough buses available. Some people called Lyft or Uber or a taxi.

BART says the problem began when two of its critical computers failed overnight.

"One powers the trains, the other tells it where to go, without those two working in harmony, we could not open," said BART spokesperson Cheryl Stalter.

What caused the failure isn't known. Overnight maintenance work has been ruled out.

BART says it's now conducting a forensic analysis to determine a cause to make sure it doesn't happen again. The investigation could take days. The glitch also prevented fare gates from closing for a time this morning, so rides were mostly free.

All trains were rolling system-wide by 11 am.