North Country Rivers was operating a commercial rafting trip in accordance with state law on Saturday when a Massachusetts man who was a Boy Scout chaperone fell out and died, the Maine Warden Service said.

In a news release Tuesday, the warden service said the fatal rafting accident in West Forks Plantation was “a rare incident involving Maine’s whitewater rafting industry, as it has been several years since a fatality has occurred.”

Michael Arena, 52, of Lexington, Massachusetts, was on a commercial rafting trip with North Country Rivers, a whitewater rafting outfitter out of Bingham, when he fell out of the raft as it was going through a series of whitewater rapids on the Dead River. The warden service responded to a report of an unresponsive man about 2 p.m.

Arena was a chaperone with a group of four Boy Scouts, one of whom was his son, according to the warden service. There were seven people in the raft, including a guide, two chaperones and four teenage boys, the service said.

Upper Kennebec Valley Ambulance pronounced Arena dead at the scene. The warden service said Tuesday that Arena’s cause of death has not yet been determined.

Sgt. Chris Simmons, with the Maine Warden Service, told WickedLocal.com of Lexington, Massachusetts, that Arena likely drowned as he was pushed under strong turbulent waves.

Reached by phone Tuesday, Jim Murton, the owner of North Country Rivers, declined comment. On Monday, Murton would only say that “the rafting trips are safe. There are no problems at all with the trips. It was an accident.”

Hank Manz, the scoutmaster for Troop 160 in Lexington, Massachusetts, said Tuesday he didn’t know additional details of the accident — he was not on the trip — and he intentionally has not questioned anyone from the troop involved in the trip, in order to “let the authorities do their investigation.”

Manz called the incident an “incredible tragedy.”

“Here at the local level, we are focused on support of the Arena family and the Scouts and adults on the trip,” Manz said. “The first thing we want to do is minimize anymore upheaval and pressure in their lives.”

The warden service said nearly 70,000 people commercially raft Maine’s rivers each year.

Cpl. John MacDonald, a warden service spokesman, did not immediately respond to a call Tuesday seeking further comment.

Manz said that about a dozen Scouts and six adults traveled to Maine for the rafting trip. He wasn’t sure if they had previously used the services of North Country Rivers. “We do some sort of outdoor trip every month, and most Scout troops do that, and we have certainly done whitewater rafting before,” he said.

Troop 160 has more than 80 Scouts and many adult volunteers and chaperones like Arena who “are a huge part of making Scouting available,” Manz said.

Manz declined to talk about Arena personally, saying that was more appropriate for family members, who were not available for comment.