Derailed Amtrak train car dangles over interstate in Washington state

(CNN) -- At least three people were killed and more than 100 injured when an Amtrak passenger train derailed in Washington state, DuPont Fire Chief Larry Creekmore said Monday night.

The Amtrak Cascades 501 was making its first trip on a new service route when the train ran off the track near DuPont, spilling 13 cars off an Interstate 5 overpass onto rush hour traffic below, authorities said.

All the deaths were contained to the train, said Ed Troyer, the Pierce County Sheriff's Office spokesman.

All southbound lanes of the interstate are closed due to the derailment and the sight stunned motorists heading to work. The incident took place near DuPont, between Tacoma and Olympia.

"I was traveling to work this morning along I-5 and we came to a sudden stop," Greg Mukai told CNN by phone. "We all tried to stop quickly to avoid running into each other to be honest. Once we all came to a stop I was able to look up and see, unfortunately, this scary thing of ... a train hanging off of the overpass. Lots of military personnel and people ran to try to help the best they could."

Latest developments:

-- More than 100 were transported to hospitals in Pierce and Thurston counties, Creekmore said. Four of them suffered serious injuries, said Cary Evans, spokesman for CHI Franciscan Health.

-- Thirteen cars jumped the track. The train had 14 cars, including two engines, said Brook Bova of the Washington State Patrol

-- A passenger on the train says his car derailed and everyone "catapulted" into the seat in front of them

-- Several fatalities have been reported among people on the train, one official said

-- Injuries have been reported among motorists on the highway whose vehicles were struck by the falling train cars, Pierce County says

-- Photos from the scene show at least one train car on the road, with another dangling over it

Danae Orlob told CNN there was a semi and a crushed truck underneath the train cars.

"We came around the corner and it had to have just happened... there were no police there yet. There was one link of the train off to one side and the other on the other side of the freeway. There were crushed cars underneath. There was an insane amount of fire trucks and ambulances heading towards us."

Amtrak said it is aware of the incident involving the 501 train, which travels from Seattle to Portland, Oregon.

According to an online schedule, the 501 train is one of Amtrak's Cascades trains, which they say "connect 18 cities along the I-5 corridor including Seattle, Portland, Vancouver, BC, and Eugene, Oregon."

Amtrak service south of Seattle is temporarily suspended. Service from Seattle to points north and east is continuing to operate, Amtrak said.

The National Transportation Safety Board tweeted that it is gathering information about an accident involving an Amtrak passenger train near Seattle, Washington.

Washington Gov. Jay Inslee tweeted, "Thank you to the first responders on the scene. We're praying for everyone on board the train, and ask everyone to hold them in your thoughts."

Image from the Department of Transportation in Washington