A train carrying Republican members of Congress to their retreat at Greenbrier resort in White Sulphur Springs, West Virginia,. One of the passengers in the truck, Christopher Foley, 28, of Louisa County, was killed in the collision, Albermale County officials said.
A passenger and the driver of the truck were injured, officials said. According to Amtrak, two crew members and two passengers on the train were transported to University of Virginia Medical Center.
President Trump, who was fully briefed on the situation, told reporters Wednesday afternoon that he had just spoken to House Speaker Paul Ryan, who had told him that lawmakers had undergone a tremendous jolt, but that they would proceed to their conference. He said Ryan told him it was a pretty rough hit. Ryan was on the train with his family, and all were unharmed. The president's remarks came during a photo op during a meeting with taxpayers.
The lawmakers were scheduled to spend the next few days at the West Virginia resort for their annual issues conference.
"I couldn't be prouder of the people on this stage ... the atmosphere was very professional," one official said during a press conference Wednesday evening. "This brings back thoughts of family and friends in a partisan Washington."
"This makes me think that this man who is deceased is going to be missed," Sen. Jeff Flake of Arizona said. He was one of the passengers who tended to the injured. "I'm just grateful for medical professionals all around and were able to apply their skills."
The White House also said in a statement that in addition to the fatality that there had been one serious injury.
"There are no serious injuries among members of Congress or their staff," the statement continued. "Senior Administration officials are in regular contact with Amtrak and state and local authorities. Our thoughts and prayers are with everyone that has been affected by this incident." Two crew members and three passengers were transported to a local hospital for treatment of their injuries, according to Amtrak.
NTSB officials held a late Wednesday press conference to announce that the on-scene investigation will last several days.
Earl Weener said the team will look at different areas of focus involved in the accident. They will also look into the operator of the Amtrak train -- including his/her health -- and also into the area where the crash happened in terms of the track and guard arms.
Weener said they are retrieving the event recorder to be inspected in a lab setting -- as soon as they can find them.
"If we find anything that indicates this was intentional, we will turn that over to the FBI," Weener said.
The specially chartered Amtrak train departed Union Station in Washington, D.C. at about 8:30 a.m., and the train hit the back of a trash truck at about 11:20 a.m. in Crozet, Virginia. The impact threw train passengers from their seats, but so far, lawmakers appear not to have sustained major injuries. Many are also traveling with their spouses and staff.
Rep. Bruce Westerman, R-Arkansas, told CBSN in an interview that as far as he knows, "Everyone on the train is fine." Westerman was still on the train during the interview. He thought the train was still operable.
Another lawmaker told CBSN that some members jumped from the train to offer help to the people in the truck who were injured.
Rep. Jeff Denham, R-California, tweeted a photo of damage to the front of the train.
President Trump is meeting with his national security team but is aware of the accident, White House press secretary Sarah Sanders said.
Amtrak released a statement on the incident that said the train "came into contact with a vehicle that was on the tracks at 11:20 a.m. in Crozet, Va. There are no reported injuries to passengers or crew members. Local law enforcement is investigating the incident and crews are inspecting equipment for damage."
CBS 19 reporter Laura Perrot is on the scene and tweeted a photo from the crash.
The front half of the truck was crushed in the accident. Congressman Steve Daines, R-Montana, tweeted from the train that he's ok, but called for prayers for the drivers of the truck.
Flake said the incident reminded him of the shooting ofat a GOP baseball practice last year.
"I thought then I never want to experience a day like this again," he said. "Unfortunately, it came too soon."
Wednesday night, Minnesota Rep. Jason Lewis' staff tweeted that the first-term congressman was taken to the hospital and was later released after suffering a concussion.
Highway and rail crossing incidents have increased in recent years. An Federal Railroad Administration report found that the increases were likely due to higher traffic volumes. According to a recent report from 2010-2014 there was an average of 2,100 incidents per year of these collisions between trains and vehicles.
Vice President Mike Pence addressed the event Wednesday night: "It's been a harrowing day for all of you."
Pence, a former House member, said he has fond memories of the retreat and the train rides back and forth. "Just know our hears are with you," he said.
CBS News' Nancy Cordes, Jeff Pegues, Arden Farhi, Jacqueline Alemany and Peter Martinez contributed to this report.