FOXBOROUGH, Mass. — Of the seven funerals, Albert Mazza Jr.’s was the last. It seemed fitting, since he had been their leader. A few years ago, he had helped establish the Jarheads Motorcycle Club, a motley crew of honorably discharged Marines who raise money for veterans in need.

In a subculture where some clubs cultivate an outlaw image, the Jarheads stood for just the opposite. As former Marines, they celebrated self-sacrifice and safety. They rode for charitable causes, including Toys for Tots, and spent one Saturday a month bringing home-cooked meals to wheelchair bound veterans in a spinal cord unit.

Last month they were on their way to an American Legion post in New Hampshire for their annual meeting when a driver with a history of drug arrests plowed his pickup truck into them.

As the club’s president, Mr. Mazza, who was known as Woody, had been the first in the line of 15 motorcycles. He died, along with six other people in what is believed to be the deadliest accident involving motorcycles in recent United States history. To a group of combat veterans, it had felt just like an I.E.D. explosion. The world upended in an instant. Shreds of flesh and metal flew. The truck burst into flames.