- Amtrak passenger train derailed near city of Tacoma
- Train was carrying 78 passengers, five crew
- Cars were thrown off a bridge, rush hour traffic was snarled
The train, which was carrying 78 passengers and five crew, derailed in DuPont about halfway between Tacoma and the state capital Olympia on a curve that passes over busy Interstate 5 at about 7:40 am (1540 GMT).
Pictures from the scene showed one Amtrak train car overturned and crushed on the interstate highway and others dangling from the overpass.
Several other carriages of the 14-car train also ended up on the highway, shutting down a key section of the busy artery that connects the greater Seattle metropolitan area to Olympia.
Officials gave no reason for the derailment of southbound Amtrak train 501, the inaugural run of a new service that promised faster connections between Seattle and Portland, Oregon.
Local officials had warned only weeks ago that the track still might not be safe enough to handle trains at higher speeds.
Officials confirmed several people had died in the crash, but declined through the day to provide precise numbers.
"There are multiple fatalities," said Ed Troyer, spokesman for the Pierce County Sheriff's Department.
"It's pretty horrific," he said.
Local television KOMO News reported six dead and several people in critical condition among the dozens sent to local hospitals for treatment.
Troyer said that it was too unsafe to check some of the cars but it was possible there were more bodies in them.
"We just don't know until they can shore up those train cars and get in there and search them," he said.
None of the people in vehicles travelling on the highway below the train were killed, according to Troyer.
The National Transportation Safety Board has sent a team of experts to investigate the incident.
'People were screaming'
Chris Karnes, a local transit official who was aboard the train, told local CBS News affiliate KIRO-TV that the accident took place while it was going around a curve.
"All of a sudden, we felt this rocking and creaking noise, and it felt like we were heading down a hill," he 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."
A conductor in one of the two engines on the train placed the emergency call.
"Amtrak 501, emergency emergency emergency, we are on the ground," he said, according to an audio recording of the call.
"We got cars everywhere and down onto the highway," he said.
Amtrak president and co-chief executive Richard Anderson said he was "deeply saddened" by the crash.
"We will do everything in our power to support our passengers and crew and their families," Anderson said.
The accident marred the launch of faster services on the route after a $181 million upgrade project that included improving the rails, the signalling technology and the locomotives.
Local officials had worried about trains going at higher speeds through the curves in the area. The trains were expected to reach speeds of 79 miles (127 kilometers) per hour through the densely populated area with the improved systems and track.
In early December, Don Anderson -- the mayor of Lakewood, Washington, a Tacoma suburb just a few miles from the accident site -- had warned that more needed to be done to ensure safety on the route.
"Come back when there is that accident, and try to justify not putting in those safety enhancements," he said, according to KOMO News.
Karnes said the tracks were supposed to have been upgraded to accommodate higher speeds.
"I'm not sure what happened," he said.
Trump: US needs better infrastructure
US President Donald Trump said the accident underscored the need to invest in infrastructure.
"Seven trillion dollars spent in the Middle East while our roads, bridges, tunnels, railways (and more) crumble! Not for long!" he tweeted.
The new Siemens Charger locomotives were equipped with "positive train control" safety systems, designed to automatically stop the train in dangerous situations and mandated for trains around the country.
But the technology was only expected to be used next year when it is activated on the entire rail corridor, according to the Washington State Department of Transportation.
In 2015, an Amtrak train going far over the designated speed for a stretch of curves in the track in Philadelphia derailed, killing eight.
At the time, analysts said positive train control technology could have prevented the accident.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)