A crash involving a big rig on U.S. Highway 101 near South San Francisco caused a fuel spill and knocked out power to Caltrain overhead lines, authorities said.

A big rig jackknifed, spilled more than 100 gallons of fuel onto a Peninsula highway, and caused an interruption to Caltrain trains early Thursday, authorities said. It was just one of two wrecks — the other occurred on an East Bay freeway — that made it a brutal morning for commuters.

A truck crash on Highway 101 early Thursday morning brought down power lines and spilled 160 gallons of fuel, causing major delays for Caltrain service between San Francisco and South San Francisco. The crash occurred around 5 a.

A two-vehicle crash involving a jackknifed big rig on Southbound 101 near South San Francisco spilled 160 gallons of fuel, caused major backups, and impacted Caltrain service.

Caltrain lost power Thursday morning from San Francisco to South San Francisco after a major truck crash on Highway 101 knocked down a fence onto power lines and spilled fuel, according to transit agency.