Cars from an Amtrak train that derailed above lie spilled onto Interstate 5, Monday, Dec. 18, 2017, in DuPont, Wash. The Amtrak train making the first-ever run along a faster new route hurtled off the overpass Monday near Tacoma and spilled some of its cars onto the highway below, killing several people, authorities said. (Bettina Hansen/The Seattle Times via AP)
Cars from an Amtrak train that derailed above lie spilled onto Interstate 5, Monday, Dec. 18, 2017, in DuPont, Wash. The Amtrak train making the first-ever run along a faster new route hurtled off the overpass Monday near Tacoma and spilled some of its cars onto the highway below, killing several people, authorities said. (Bettina Hansen/The Seattle Times via AP) Credit: Bettina Hansen

DuPont, Wash. — An Amtrak train making the first-ever run along a faster new route hurtled off an overpass south of Seattle on Monday and spilled some of its cars onto the highway below, killing at least three people, injuring more than 100 and crushing two vehicles, authorities said.

Attention quickly turned to the train’s speed. A website that maps location and speed using data from Amtrak’s train tracker app showed the train was going 81.1 mph about a quarter of a mile from the point where it derailed, where the speed limit is significantly lower.

Seventy-seven passengers and seven crew members were aboard when the train derailed and pulled 13 cars off the tracks. Authorities said there were three confirmed deaths and more than a dozen people with critical or serious injuries.

About two hours after the accident, a U.S. official who was briefed on the investigation said he was told at least six people were killed. No additional briefings were provided by late afternoon, and the official said he had no new information to explain the discrepancy in the numbers.

The official was not authorized to discuss the investigation publicly and spoke to The Associated Press on condition of anonymity.

A track chart prepared by the Washington State Department of Transportation shows the maximum speed drops from 79 mph to 30 mph for passenger trains just before the tracks curve to cross Interstate 5, which is where the train went off the tracks.

The chart, dated Feb. 7, 2017, was submitted to the Federal Railroad Administration in anticipation of the start of passenger service along a new bypass route that shaves 10 minutes off the trip between Seattle and Portland.

It was not clear how fast the train was moving at the precise moment when it derailed.

Kimberly Reason with Sound Transit, the Seattle-area transit agency that owns the tracks, confirmed to the AP that the speed limit at the point where the train derailed is 30 mph.

In a radio transmission immediately after the accident, the conductor can be heard saying the train was coming around a corner and was crossing a bridge that passed over Interstate 5 when it derailed. Dispatch audio also indicated that the engineer survived with bleeding from the head and both eyes swollen shut.

“I’m still figuring that out. We’ve got cars everywhere and down onto the highway,” he tells the dispatcher, who asks if everyone is OK.

Aleksander Kristiansen, a 24-year-old exchange student at the University of Washington from Copenhagen, was going to Portland to visit the city for the day.

“I was just coming out of the bathroom when the accident happened. My car just started shaking really, really badly. Things were falling off the shelf. Right away, you knew that this was not something minor,” he said.

The back of his train car was wide open because it had separated from the rest of the train, so he and others were able to jump out to safety. He was at about the middle of the train, either the sixth or seventh car, he said, and was “one of the lucky ones.”

The new bypass was built on an existing inland rail line that runs along Interstate 5 from Tacoma to DuPont, near where Train 501 derailed. Track testing began in January and February in advance of Monday’s launch and continued through at least July, according to the Washington State Department of Transportation.