A passenger train carrying Republican members of the U.S. Congress to a retreat in West Virginia slammed into a garbage truck on Wednesday at a rural Virginia road crossing, killing one person on the truck, authorities said.

No major injuries were reported among the lawmakers or staff on the train, the U.S. Department of Transportation said. There was one serious injury among those on the truck, in addition to the fatality.

Amtrak, the U.S. passenger rail service that operated the chartered train, said two crew members and three passengers were hospitalized with minor injuries after the crash. One, Representative Jason Lewis, was examined for a possible concussion.

“I‘m fine compared to, tragically, the truck drivers, and thankful for the prompt action of our doctors and first responders. My thoughts are with the family of the driver who passed away,” Lewis told Reuters.

The train was taking lawmakers to the annual retreat in White Sulphur Springs, West Virginia, just west of the Virginia state line. Amtrak said the collision occurred at 11:20 a.m. in Crozet, a tiny town between the college town of Charlottesville, Virginia, and White Sulphur Springs.

Lewis later left the hospital and traveled to the retreat, where he intended to participate as much as he was able, a spokeswoman said.

Senator Bill Cassidy, a doctor, said he and other lawmakers who had medical training tended to the injured until emergency personnel arrived.

The truck was on the tracks at a crossing when the crash occurred, Amtrak said. Video from the scene showed the battered truck afterward, with trash strewn around it.

“We were going along the Virginia countryside at pretty good speed,” Senator Jeff Flake said in comments released by his office. “All of a sudden, we felt an impact and obviously heard a pretty loud noise. Most of us were thrown a bit in our seats and those of us who were standing were really thrown.”

Spouses and children of some lawmakers were aboard. House of Representatives Speaker Paul Ryan was on the train, but Senate Majority Leader Mitch McConnell was not.

LAW ENFORCEMENT

Immediately after the crash, a law enforcement team surrounded the train with weapons drawn and searched the area for possible attackers while the injured were treated, said a local emergency worker, speaking on condition of anonymity.

“They surrounded the train on both sides and set up a perimeter with their automatic weapons pointing out and then searched the woods around the train,” the worker said. “At least five members of Congress helped firefighters and EMTs (emergency medical technicians) treat the three injured people who had been in the truck.”

The Republican retreat, an opportunity for lawmakers to discuss legislation and politics in the run-up to November’s congressional elections, was scheduled to run until midday on Friday. President Donald Trump was due to attend on Thursday. Vice President Mike Pence attended on Wednesday.

Trump told reporters at the White House he had spoken to Ryan and others, calling the accident “a pretty rough hit.”

“We don’t have full understanding yet as to what happened,” Trump said.

The National Transportation Safety Board said its investigators arrived at the scene of the crash about four hours later. NTSB member Earl Weener told reporters the on-scene investigation was expected to last several days, “followed by months back at headquarters.”

Investigators will examine whether the gate crossing, lights and other safety mechanisms were working properly, Weener said.

”The NTSB does safety investigations,” Weener said. “If we find anything that indicates this was intentional, we will hand it over to the FBI.”

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 approach.

It was the second tragedy to hit congressional Republicans in the past year.

In June, a gunman opened fire at a field outside Washington where Republicans were practicing for a charity baseball game. Representative Steve Scalise, the No. 3 House Republican, was severely wounded, but has returned to work.

He was not on the train on Wednesday.

While it was not immediately clear who was at fault in the collision, Amtrak’s safety record has come under scrutiny after a series of incidents including a derailment south of Seattle in December that killed three. In that crash, an engineer misread a signal and failed to slow the train, investigators said.

Amtrak is partly government funded, but is operated and managed as a for-profit corporation.