LIVE: Passengers killed when Amtrak train on new route derails in Washington state

An Amtrak passenger train derailed on Monday during its inaugural run along a faster route through Washington state, sending part of the train crashing down onto a major highway and killing an unknown number of passengers, authorities said.

The derailment caused "multiple fatalities," Ed Troyer, a spokesman for the local sheriff's office, told reporters at the scene, though he did not offer a specific number. The train struck several cars on Interstate 5, he added, causing injuries but no additional deaths.

Seventy-seven people were transported to hospitals in Pierce and Thurston counties, the Tacoma-based CHI Franciscan Health healthcare network said. Four of them were considered "level red" patients with the most severe injuries.

About 78 passengers and five crew members were aboard the train, Amtrak said in a statement.

Some people escaped by kicking out windows, passenger Chris Karnes told local news outlet KIRO 7.

"All of a sudden, we felt this rocking and creaking noise, and it felt like we were heading down a hill," Karnes said. "The next thing we know, we're being slammed into the front of our seats, windows are breaking, we stop, and there's water gushing out of the train. People were screaming."

The derailment occurred on the first day Amtrak trains began using the new inland route between the cities of Tacoma and Olympia, part of a project to reduce travel time, according to an October news release from the state's transportation department.

(Map of derailment site - https://tmsnrt.rs/2kKt2Uy)

The rerouting takes trains along I-5, eliminating a major choke point for passenger trains in Tacoma and letting trains reach speeds of 79 miles per hour (127 km per hour), the department has said.

Monday's southbound train, which was scheduled to depart Seattle at 6 a.m. (1400 GMT) for Portland, Oregon, was the first to run along the new route, which uses tracks owned by a local commuter line.

It was not immediately clear whether the derailment, which came during a busy travel time one week before the Christmas holiday, was connected to the rerouting.

UPSIDE-DOWN TRAIN CAR

The train derailed around 7:30 a.m. (1530 GMT) in DuPont and shut down the interstate's southbound lanes. A photograph posted by Washington State Police showed an upside-down train car partially crushed on the highway, with a second car dangling off the overpass.

The National Transportation Safety Board (NTSB) was sending a team of investigators to the site, the federal agency said on Twitter, and scheduled a news conference in Washington, D.C., for Monday afternoon.

Washington Governor Jay Inslee declared a state of emergency due to "loss of life, injuries and damage to infrastructure."

U.S. President Donald Trump tweeted that the crash "shows more than ever why our soon to be submitted infrastructure plan must be approved quickly." Trump has said he will unveil his long-delayed infrastructure proposal after Congress passes its tax bill.

Interstate 5 is the West Coast's major north-south highway, running between the U.S-Mexican border in San Diego, California, and the border with Canada in Washington.

The mayor of one of the towns through which the rerouted trains travel warned earlier this month that the high-speed trains were dangerously close to cars and pedestrians.

"Come back when there is that accident, and try to justify not putting in those safety enhancements, or you can go back now and advocate for the money to do it, because this project was never needed and endangers our citizens," Lakewood Mayor Don Anderson told transportation officials in early December, according to Seattle's KOMO News.

The derailment was Amtrak's second in Washington state this year. On July 2, a southbound train with more than 250 people aboard derailed in the town of Steilacoom, just a few miles north of Monday's crash site. No serious injuries were reported.

In May 2015, an Amtrak train derailed in Philadelphia, killing eight people and injuring more than 200. The NTSB concluded the driver became distracted by radio transmissions and lost track of where he was.

(Reporting by Tom James in DuPont, Washington; Additional reporting by Jonathan Allen, Gina Cherelus, Peter Szekely and Daniel Trotta in New York; Writing by Joseph Ax; Editing by Chizu Nomiyama and

Jonathan Oatis)

Watch a live feed of the local report via KOIN below: