A chartered Amtrak train, carrying US Republican lawmakers, was travelling at 98kph, when the driver hit the brakes and fatally struck a garbage truck on the tracks at Crozet, Virginia, investigators say.
In a briefing on Thursday (local time), the National Transportation Safety Board said that the maximum speed limit at the crossing was 96.6 km/h and that preliminary data showed the driver in Wednesday's crash applied the brakes 20 seconds before the train came to rest.
A passenger in the truck - 28-year-old Christopher Foley - was killed and two others in the truck were injured, according to police. The NTSB has not been able to interview the 30-year-old truck driver.
No lawmakers were seriously injured, but Minnesota representative Jason Lewis was taken to a hospital as a precaution and released.
The train had hundreds of passengers onboard at the time of the accident, NTSB board member Earl Weener said.
The NTSB has not yet downloaded the forward locomotive video camera or event data recorder. The board said that when it reviews the video data, it should be able to determine if the signals at the crossing were working or if the truck was moving.
The train was taking lawmakers to the annual retreat in White Sulphur Springs, West Virginia. Amtrak said the collision occurred at 11.18am (local time) in Crozet, a tiny town between the college town of Charlottesville, Virginia, and White Sulphur Springs.
The Virginia Department of Transportation said the intersection where the crash occurred had flashing signals and gates to prevent motorists from getting on the tracks as trains approached.