The US passenger train that crashed onto a highway in Washington state, killing three people, was travelling at more than double the permitted speed limit, investigators have found.

On Monday morning (18 December), during the rush hour, an Amtrak train veered off the rails, plunging onto the I5 Highway.

Investigators from the NTSB, (National Transportation Safety Board) found that the train had been travelling along the bend at 80mph, despite it being a 30mph zone.

A total of 13 of the 14 carriages on the Amtrak Cascades 501 journey from Seattle to Portland derailed, with some left dangling over the road.

Officials from the NTSB have revealed the speed concerns after collecting data from the rear locomotive's event data recorder.

Much of the route is permitted to have travel at around 80mph, but the crash site, a sharp curve, requires a drop to 30mph.

Bella Dinh-Zarr from the NTSB said that the "preliminary indications are that the train was travelling at 80mph on a 30mph track. Our hearts go out to everyone who is affected by this very tragic accident."

Several cars and two lorries were hit when the train derailed, though none of the road users were killed.

More than 70 others were injured in the train and in crushed vehicles when the crash took place at around 7.40am.

There were 86 people on the train at the time of the crash including 77 passengers, seven Amtrak crew and a train technician.

The train was making its inaugural journey on a new track between Portland and Seattle.

Washington train crash derail
First responders are seen at the scene of an Amtrak passenger train derailment on interstate highway (I-5) Brooke Bova/Washington State Patrol/Handout via REUTERS