SAN FRANCISCO, Dec. 18 (Xinhua) -- At least six people were killed and 22 others taken to three hospitals after an Amtrak train derailed near Tacoma in the U.S. Washington state Monday, local media reported.

The Washington State Patrol said altogether 13 of the 14 total cars of Amtrak train 501 derailed south of Seattle in Washington state on the U.S. west coast.

At least one rail car fell off a bridge over a traffic-clogged highway, while five motor vehicles and two semis were hit on freeway below.

Despite the lack of accurate official account of deaths and injuries, MultiCare Health, a non-profit network of hospitals and clinics, said 22 people were taken to three hospitals for treatment of injuries from the derailment of the AMTRAK train near Tacoma in Washington state.

"Victims from the Amtrak train that derailed in DuPont are at 3 of our hospitals," it tweeted earlier.

The Pierce County Sheriff's Department of Washington state said it has not released any numbers on fatalities in the Amtrak train derailment at the moment.

The Amtrak train running between Tacoma and Portland, Oregon derailed and overturned in the Pierce County.

The National Railroad Passenger Corporation, or Amtrack, said in a statement that 78 passengers and five crew members were on board the train at the time of the crash.

Amtrak said in an earlier tweet that Amtrak service south of Seattle is temporarily suspended, but service from Seattle to points north and east is continuing to operate.

The U.S. National Transportation Safety Board said it's too early to know if the crash was due to high speed.

Bella Dinh-Zarr, spokesperson for NTSB, said a team of 20 investigators will be at the scene later Monday evening.

U.S. President Donald Trump also offered "thoughts and prayers" on Monday for those involved in a train derailment in Washington state.

Founded in 1971 and headquartered in Union Station in Washington, D.C., Amtrak is a passenger railroad service that provides medium- and long-distance intercity service in the contiguous United States.

Amtrak serves more than 500 destinations in 46 U.S. states and three Canadian provinces with more than 300 trains running over 21,300 miles (34,000 km) of track every day.

In fiscal year 2016, the company, which employs more than 20,000 people, served 31.3 million passengers and earned about 3.2 billion U.S. dollars in revenue.

Nearly two-thirds of its passengers come from the 10 largest metropolitan areas.