WHITTIER (CBSLA) — A Union Pacific train has derailed Wednesday in Los Nietos, near Whittier, damaging Amtrak and Metrolink tracks under the Slauson Boulevard overpass.

The train derailment happened at about 10:45 a.m. Wednesday.

No injuries have been reported. But due to an apparent chemical spill, the Slauson Avenue offramp from the 605 Freeway is being closed until at least 4 p.m., according to the California Highway Patrol.

Afternoon commutes will be affected, with Amtrak saying they have no estimated time of tracks reopening between Fullerton and Los Angeles.

Passengers will be diverted to buses.

This is a breaking news report. More information will be added as it comes in.