Crews were repairing the tracks between the Lake and Sierra Madre Villa stations. On Thursday, a tractor-trailer blew a tire, lost control and sideswiped a box truck, according to the California Highway Patrol.
Friday night, Metro opened one Gold Line track between Lake and Sierra Madre Villa stations with limited service.
The tractor-trailer then veered across lanes and crashed onto the Metro Gold Line tracks and hit an energized power pole.
Hazmat teams may be called in to clean up the oil. It was unknown when the line would be back up and running.
Shuttle buses were showing up every five minutes.