An hours-long systemwide BART service disruption Saturday was caused by a software failure at one switch, according to BART officials.
The problem started at 2:45 a.m. Saturday and it took until nearly 11 a.m. for normal service to be restored.
"The failure was software related at one switch that is part of a complex computer network," BART spokeswoman Alicia Trost said in a new release Monday.
Limited service was restored by about 9 a.m. but normal operations didn't begin until 10:50 a.m.
BART is still looking into what exactly caused the failure but has determined that it wasn't due to overnight work being done on the system, Trost said.