LANCASTER, N.H. >> Investigators pleaded today for members of the public to come forward with information that could help them determine why a pickup truck hauling a trailer collided with a group of 10 motorcycles on a rural highway, killing seven bikers.

The crash in remote northern New Hampshire involved members of Marine JarHeads, a motorcycle club that includes Marines and their spouses, authorities said. The tragedy sent shockwaves through New England’s communities of motorcyclists and military veterans, which often overlap.

“When something like this happens, we all feel it,” said Cat Wilson, who organizes a motorcycle charity event in Massachusetts and is a friend of some of the crash victims. “There is no tighter community than our biker community.”

Authorities identified the pickup driver as Volodoymyr Zhukovskyy, 23, an employee of a Springfield, Massachusetts, company called Westfield Transport.

Zhukovskyy survived the accident, did not need to be hospitalized and has not been charged, authorities said, but they didn’t address details on his whereabouts. A phone listing for him couldn’t be found.

Dartanyan Gasanov, the owner of Westfield Transport, told The Boston Globe that he planned to talk to investigators Monday and has been unable to reach Zhukovskyy, who has not been answering phone calls.

The National Transportation Safety Board is among the agencies investigating. Authorities asked for the public’s help in the form of videos, photos or other information about the accident or the vehicles involved.

“This is one of the worst tragic incidents that we have investigated here in the state,” New Hampshire State Police Col. Chris Wagner said at a news conference in nearby Lancaster. “It’s going to be a very lengthy investigation.”

A black 2016 Dodge 2500 pickup truck towing a flatbed trailer of the kind used to haul cars collided with the bikers around 6:30 p.m. Friday on U.S. 2, a two-lane highway in Randolph, police said. Randolph is about a two-hour drive north of Concord, the capital, and a three-hour drive from Boston.

Along with the seven dead, state police said, three people were taken to hospitals. Two of them were released today. Police did not provide names of the injured or dead but said they could release the names of victims as early as Sunday.

The road reopened today, when skid marks were still visible for several hundred feet on the road, which has mountains and fields full of wildflowers as a backdrop. Nothing was left of the broken motorcycles, but a patch of burned grass and tire marks in the mud remained.

For much the day, residents and bikers stopped by to pay respects. Some prayed, reminisced about their own close calls or planted American flags.

Bill Brown, a 73-year-old Vietnam veteran and motorcyclist, arrived at the scene near a gentle curve in the road to put down flags, calling the victims “brothers in arms,” vowing to keep riding and expressing shock.

“Seven people. C’mon. It’s senseless,” he said. “Somebody make a mistake, and it turned out to be pretty deadly.”

Down the road, over a dozen members of the Marine JarHeads gathered at a motel. Dressed in motorcycle jackets with “JarHeads” written on the back, they hugged one another and wept. Earlier in the day, they prayed with a pastor.

Members of the motorcycle community are already organizing help for the victims’ families, Wilson said.

A small memorial was held at a church in nearby Berlin this evening.

On Friday, witnesses described a “devastating” scene as bystanders tried to help riders lying in the road. Broke motorcycles and the bodies of riders littered the highway and the pickup sent off the road and burst into flames.

“There was debris everywhere,” said Miranda Thompson, 21, of Manchester, who was several cars back and recalled seeing a truck in flames on the side of the highway and six motorcycles.

“People were in the grass,” she said. “There were people putting tourniquets on people, trying to make sure they didn’t move.”