Threat relayed via 911 prompts closure of tracks in Oakland and snarls Friday morning rush hour.
Most Bay Area transit agencies are on a Sunday schedule.
Testimony comes as jury hears suit from imprisoned father over fatal shooting of his son in 2009.
Cost could go as high as $6 for trains, which will arrive every four minutes and take Clipper.
Late-night fatality shut down early-morning service between Hayward and Fremont stations.
Computer-operated system fails, leading to major delays through the system. Caltrain bogs down, too.