SEATTLE — An Amtrak train that derailed Sunday was traveling through a section of track that contains a switch that will nudge a train off-course if the draw-span on the approaching bridge is open.

The Seattle Times reports it's not known if that switch caused the derailment.

Officials continue to investigate how the Amtrak Cascades 506 went off-track with 267 people aboard. Some suffered minor injuries.

Sunday's train was heading north from Oregon when it derailed 50 to 100 yards before the Chambers Bay drawbridge south of Tacoma.

That span crosses Chambers Creek.

On either side are switch-like devices known as "derails" between the twin rails. They're used nationwide. They could prevent a catastrophe if a train were hurtling toward a partly or fully opened draw-span.

Amtrak has declined to comment on possible causes.

— The Associated Press