PACOIMA, Calif. (CBS) — A Union Pacific train derailed Tuesday morning in Pacoima.

Authorities said the derailment occurred when two cars came off the track around San Fernando Road and Sheldon Street in Burbank.

Aaron Hunt of Union Pacific said the cars had been carrying rocks but were empty at the time they derailed.

No one was injured in the incident.

The cause of the derailment remained under investigation.

Officials say trains were running on schedule Tuesday afternoon.