The train that derailed near DuPont Monday morning was traveling too fast when it entered a curve.

Photos of the scene

The Washington State Patrol confirmed three people were killed.

According to a spokesperson for the National Transportation Safety Board, data from the train shows the train was traveling “at 80 mph on a 30 mph track.”

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What remains unclear is why the train was traveling as fast as it was. The train was part of a new high-speed service from Seattle to Portland. It was a new route, but testing had been done before the inaugural run. And the speed limit was posted.

The NTSB says it’s too early to tell why the train was traveling so fast.

There were 80 passengers and five crew members on the train that consisted of 12 cars and two locomotives. Seventy-two people were hospitalized when all but one locomotive left the tracks — 10 were in serious condition and another 13 had minor to moderate injuries. Only 19 people walked away uninjured.

Additionally, five passenger vehicles and two semi-trucks were involved in the derailment when a train car fell off the overpass over I-5.

The Seattle Times quoted Russell Quimby, a former NTSB consultant, who says the track appeared relatively undisturbed, and it didn’t look like anything knocked the train off the track — the lead engine just went in a straight line instead of following the curve.

The question now is: Would an automatic braking system have prevented this?

“PTC (positive train control) would prevent types of accidents such as this,” NTSB spokesperson Bella Dinh-Zarr said.

Whether it would have prevented this deadly derailment remains to be seen.

According to Sound Transit, which built the new tracks, the necessary track equipment was installed. But when the president of Amtrak was asked this question: “I understand that the track was run by Sound Transit. Was positive train control activated on those tracks?” His answer was, “No.”

Originally, Congress set a deadline of 2015 for completing the control system across the country. That has since been pushed back to December 2018.

This is the third fatal passenger train crash that appears to be due to speed — there was the 2013 Metro-North commuter train crash in the Bronx and the 2015 Amtrak crash in Philadelphia.