The 23-year-old cyclist from Massachusetts who was killed last week on the opening day of the annual Trek Across Maine most likely lost his balance while he was sipping from a water bottle and fell into a passing tractor-trailer, state police said Monday.

David LeClair, riding with a large team from his employer, athenahealth, was among more than 2,000 riders who started the fundraising ride Friday morning at the Sunday River ski resort in Newry. He was only a few miles into the ride when he was hit by a truck hauling bulk corn on Route 2 in the Oxford County town of Hanover.

An autopsy by the state medical examiner showed that LeClair died of head injuries, and that the truck may have hit his left arm, police said. LeClair’s head either hit the truck as it passed in the 40 mph zone or hit the pavement, killing him instantly, police said.

The force of the truck hitting his left arm may have accelerated his fall, police said.

Police interviewed several of LeClair’s fellow riders and viewed videotape from a police cruiser and a local business in their effort to determine what happened.

The tapes did not show the accident itself, but did confirm that the Canadian truck that police stopped five miles away in Rumford was involved.

State police Lt. Walter Grzyb said troopers still have a significant amount of investigating to do before an accident report is complete, but they believe they have a good idea of how the accident occurred.

“He pulled his water bottle out and he’s taking a drink of water. He has the left hand on the handlebar, a little less stable than two (hands),” Grzyb said. “The truck comes by, creates a draft, suction, whatever, and he just loses his balance and over he goes.

“He fell down into the path of the truck and he was struck,” Grzyb said,” as opposed to being knocked off his bicycle by contact with the truck.

The tractor-trailer was 3 to 4 feet from the bicycle just before the accident, witnesses told police. The truck was in the travel lane, and the cyclist and others were in the breakdown lane, riding two or possibly three abreast.

As the accident occurred, one other cyclist fell or tipped over as he stopped but was not injured, Grzyb said.

Police have not determined how fast the truck was going, in part because it did not collide with the bicycle. A collision would have given them a way to measure the force of the impact, which could indicate the truck’s speed.

The speed limit on the road drops from 55 mph to 40 mph just before the area where the accident occurred.

Commercial vehicles have event data recorders, similar to the black boxes on aircraft. But the devices record only a few seconds of information at a time, and by the time the truck was stopped, the data that was recorded at the time of the accident had been written over, Grzyb said.

Troopers will look at any global positioning system information that might aid in the investigation, he said.

The accident occurred on a stretch of road with a relatively wide shoulder. There were at least 5 feet between the guardrail and the white line separating the breakdown lane from the eastbound travel lane, police said Friday. The roadway is wider there than on other parts of the Trek Across Maine’s 180-mile route, police said.

Although it has not been confirmed by video, witnesses told police that there was westbound traffic at the time, which would have limited how wide a berth the truck could have given the cyclists.

Police used video from a nearby business and the Rumford police cruiser that was first on the scene to confirm that the truck involved was the one that police stopped.

The video showed traffic on the road before and after the truck passed, confirming that police stopped the truck that witnesses described, Grzyb said.

Police say it’s unlikely that charges will be filed against the driver of the truck, Michel Masse-DeFresne, 24, of Quebec, but the results of the investigation will be turned over for the Oxford County district attorney to review when it is completed, in about a month.

Masse-Defresne has no record of driving violations in Maine, according to the Maine Bureau of Motor Vehicles. The province of Quebec does not allow public access to a person’s driving record, according to a website maintained by the province.

The company that the truck was being driven for, Transport Beauregard, has not had a crash with injuries within the past two years, according to the Federal Motor Carrier Safety Administration.

But the rate at which Beauregard’s drivers and vehicles have been taken out of service exceeds national averages, according to the administration’s website. 

Out of 11 drivers inspected over the two years, one was stopped for safety reasons, because the person had exceeded the allowable hours behind the wheel.

Of eight trucks inspected, two were taken out of service because of violations, the agency said. Neither one was the truck involved in Friday’s accident. The agency had no records of violations involving that truck.

The company is operating under a conditional status after a compliance review in January 2012. The violations all occurred in the U.S.

It was not clear whether the truck involved in Friday’s accident is owned by Transport Beauregard or another entity. A person who answered the phone Monday at Transport Beauregard said the owner, Serge Beauregard, was out of the office and was the only person authorized to talk.

Companies often hire trucks from other companies to haul loads; the trucks’ owners are responsible for their maintenance, according to the Federal Motor Carrier Safety Administration.

Will Schaefer, who heads vehicle programs for the Maryland-based Commercial Vehicle Safety Alliance, said he is familiar with the effects of wind created by a passing vehicle, and is an avid cyclist.

“When any vehicle is traveling down the road, it has to displace the air and push the air out to go through it,” said Schaefer.

“At the back of the vehicle, after it goes by, the air is going to fill in behind it, and a lot of times behind a truck there is a lot of turbulence,” he said. “That turbulence, I don’t believe, in and of itself would draw a cyclist under the rear wheels, for example, but it could have some impact on the cyclist if he is not paying attention. It is something that would have an impact on any vehicle, including a cyclist passing by, if the (truck) was close enough.”

David Hench can be contacted at 791-6327 or at:

[email protected]