Altamont Corridor Express train service is shut down for all of Thursday because of a gas leak reported in Livermore overnight, authorities said.
Union Pacific Railroad was notified around midnight of the leak, which prompted all train traffic through the Altamont Pass to halt until the leak could be identified and repaired, Union Pacific spokesman Tim McMahan said.
PG&E spokeswoman Karly Hernandez said shortly after 8:30 a.m. that utility crews had responded and identified the leak near the trackway in the area of 4671 Las Positas Road.
Crews are "further investigating the source of the leak and will make any necessary repairs," Hernandez said.
No customers' gas service has been affected by the leak and no air quality issues are being reported, she said.
An ACE official said Union Pacific notified them around 4 a.m. that a 6-mile stretch of tracks was closed to rail traffic because of the leak. All service was then canceled for the day, according to the rail agency.