A single car crash on County Road in Oak Bluffs Wednesday afternoon claimed the life of high school senior Eric MacLean, who had just turned 18.

Mr. MacLean, a varsity ice hockey and football player planning to join the Marine Corps in September, was the passenger in a 1979 Jeep CJ-7 driven by his friend, Seamus O'Brien, also 18. The Jeep was headed north near the Meadow View Farms development when it crashed into a tree at about 2:15 p.m., ejecting both men from the car. Neither one was wearing a seatbelt, according to police.

Mr. MacLean was treated at the scene, but pronounced dead on arrival at the Martha's Vineyard Hospital at 2:55 p.m. His mother, Patricia Bergeron, a unit secretary in the emergency room, was on duty when her son arrived by ambulance. Mr. O'Brien was not seriously hurt and was treated and released from the hospital.

The accident happened just a short distance from Mr. MacLean's home and about a mile from where Mr. O'Brien lives. The collision was so severe that the vehicle just came apart, said Oak Bluffs police chief Joseph Carter.

"The car body separated from the chassis, and there were no doors on the vehicle. The occupants were thrown from the car, and MacLean suffered visible, violent trauma," Chief Carter said.

As of yesterday, state police were still investigating the cause of the crash. The Gazette has confirmed that the state police accident reconstruction team that arrived yesterday morning is looking at the possibility of mechanical failure. State police have asked mechanics at Buddy DeBettencourt's garage in Oak Bluffs to inspect the Jeep's steering mechanism.

Police could not speculate whether speed was a factor in the crash, and Chief Carter said there was no evidence that alcohol or drugs played a role. Mr. O'Brien was not tested for blood-alcohol levels, and police have filed no charges against him.

"There was no evidence to raise any suspicions," said Chief Carter. "But if we get any information about drugs or alcohol, we'll pursue it."

Less than two weeks ago, alcohol consumption was blamed in a crash that injured two high school students traveling on Edgartown-West Tisbury Road in West Tisbury.

Mr. MacLean's death sent the Martha's Vineyard Regional High School community into a state of mourning. The school remained open the last two nights with counselors from the school and Martha's Vineyard Community Services on hand to help students and parents begin to grieve the loss.

Principal Peg Regan called faculty in for a 7:15 a.m. meeting yesterday to plan out a day that included continuing counseling and assemblies where students could share memories of Mr. MacLean.

"The school is a good place for these kids to be. We have the space to give kids to talk," she said. "There's a lot of really deep grieving going on. Four kids had written a rap song for Eric."

The hardest hit students, she said, are Mr. MacLean's classmates in the senior class. Many already grieved the death of another of their own, Robert Luce, Jr., who died in a single car crash in 1999 in West Tisbury at the age of 17. And for students from Oak Bluffs, the tragedy is likely to awaken memories of the death of yet another classmate, Joey Beaulieu, who died in a 1993 boating accident. Joey Beaulieu was 10 years old, and he and Eric MacLean were pals.

"They were best friends," Patricia Bergeron said yesterday while sharing memories of her son. "He was one of those kids that challenged everybody, but he had a heart of gold. He was not academically great, and sports were a necessity. He shined at it. His proudest moments were the state hockey and football championships."

Ms. Bergeron, who spent part of yesterday morning talking with her son's classmates, said Eric was planning to join the Marines next fall.

At the Oak Bluffs School, faculty were also struggling to deal with news of the tragedy.

"The impact on the staff has been very powerful," said guidance counselor Bill Jones. "Eric was a kid that everybody loved. Everyone was so proud of every piece of success he achieved."

Back at the high school, Mrs. Regan said counselors will continue to provide support to students and especially the seniors. "It really is a traumatic blow," she said. "For these students, they're really experiencing this in a very raw and new way."

Part of the school's job yesterday, she said, was to dispel rumors. She confirmed that both Mr. MacLean and Mr. O'Brien were off-campus on Wednesday at work-study jobs. In the afternoon, they returned to the high school to pick up schoolwork for Mr. MacLean, who had been out sick with the flu. They left campus at the end of the school day, Mrs. Regan said.

Visiting hours for Eric MacLean will be held from 5 to 8 p.m. tonight at the Chapman, Cole and Gleason Funeral Home on the Edgartown-Vineyard Haven Road in Oak Bluffs. A Mass of Christian Burial will be held at 11 a.m. on Saturday, March 31, at Our Lady, Star of the Sea Church in Oak Bluffs.

Donations may be made in his memory to the Eric Bergeron MacLean Fund, c/o Martha's Vineyard Cooperative Bank, P.O. Box 668, Vineyard Haven, MA 02568 or to the Holy Ghost Society Benevolent Fund, P.O. Box 2203, Oak Bluffs, MA 02557.

Flowers now line the side of County Road where the Jeep crashed.

"Kids are talking to each other about safe driving, seat belts and not taking risk," Mrs. Regan said. "But right now, we're not trying to make this about laying down any lessons. We're just helping people get through the grieving process."