Federal officials claim the Amtrak train was travelling 80mph in a 30mph zone when it derailed south of Seattle.
Bella Dinh-Zarr, an NTSB board member, said at a Monday night news conference that information from the event data recorder in the rear locomotive provided information about the train’s speed.
Authorities say at least three people were killed and dozens injured when the train derailed early Monday morning, spilling train cars onto a busy interstate.
Dinh-Zarr said it’s not yet known what caused the train to derail and that “it’s too early to tell” why it was going so fast.
Authorities say 72 people were medically evaluated and taken to hospitals for treatment after a train derailed on to a highway, ten were considered to be in a serious condition.
The fatal derailment could intensify scrutiny of the national passenger railroad company's safety record, which was already under harsh criticism following a series of fatal incidents.

The derailment of 13 carriages of an Amtrak train in Washington State has caused "multiple fatalities". Source: AAP
Amtrak slammed for failing safety culture
The cause of Monday's accident, which killed at least three people, has yet to be determined, and it could take months for investigators from the US National Transportation Safety Board to reach a conclusion.
Just last month, the chairman of the NTSB issued a scathing critique of Amtrak's culture, saying a future breakdown was likely, and the board made nine safety recommendations.
"Amtrak's safety culture is failing and is primed to fail again, until and unless Amtrak changes the way it practices safety management," NTSB Chairman Robert Sumwalt said in a statement on November 14.
Sumwalt's statement was made when the NTSB issued its findings on a fatal Amtrak accident in April 2016 in Pennsylvania, which it said was caused by "deficient safety management across many levels of Amtrak and the resultant lack of a clear, consistent and accepted vision for safety".
There was no indication that any of the same issues played a role in the Washington crash.
In the Pennsylvania accident, an Amtrak train struck a backhoe working on railroad tracks in Chester, Pennsylvania, killing two maintenance workers and injuring 41. It occurred a few kilometres south of the site of a May 2015 derailment in which eight people were killed and more than 200 injured.
Sumwalt told a hearing the board's "investigation revealed more than two dozen unsafe conditions and not all of these were rule-breaking by frontline employees".
Amtrak this past summer named former Delta Air Lines Chief Executive Officer Richard Anderson as co-CEO.
Anderson said Amtrak takes NTSB recommendations from investigations "very seriously" and was continuing to make investments that the NTSB recommended.