LIVERMORE (CBS SF) – Utility crews located the site of a gas leak Thursday morning in Livermore that has forced the Altamont Corridor Express train service to shut down for the day, authorities said.

PG&E said the crews have shut off gas to the line but will be venting the residual gas inside before they make the repairs. The venting will start sometime “early afternoon” so people in the immediate area will be able to smell the gas.

READ MORE: Trevor Noah To Host 'The 64th Annual GRAMMY Awards' On CBS

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.

READ MORE: 'Video Music Box' Founder, Hip Hop Influencer Ralph McDaniels Shares His Journey In New Showtime Documentary: 'This Music Is Really Powerful'

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.

MORE NEWS: UPDATE: San Jose Homicide Suspects Released Without Posting Bail; Cops Tweet 'The System Has Failed'

© Copyright 2019 CBS Broadcasting Inc. and Bay City News Service. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.