Speed was a factor and charges are expected against the 17-year-old driver in the single-car accident on Edgartown-West Tisbury Road that claimed the life of 18-year-old Jena Pothier of Oak Bluffs Thursday evening, police said yesterday.

West Tisbury police chief Beth Toomey said charges will be brought against Kelly McCarron, 17, of Oak Bluffs, who was seriously injured in the crash and remains in serious but stable condition at Massachusetts General Hospital in Boston.

Chief Toomey said she could not provide more detail because the investigation remains ongoing.

“I can say the driver has been cited, but I can’t say much more than that right now. It’s an open investigation,” the chief said.

Chief Toomey did provide some details about the crash, confirming that the 2004 Toyota Camry driven by Ms. McCarron was heading up-Island on Edgartown-West Tisbury Road when it went off the road and hit a tree. Investigators believe Ms. McCarron passed a motor vehicle immediately before the accident occurred. Chief Toomey said indications are that high speed was a factor in the accident; she declined to comment on whether alcohol was a factor.

The chief also would not comment on whether the girls were wearing seat belts, although the police report confirmed that Ms. McCarron was thrown from the car.

The investigation is ongoing with the assistance of the Massachusetts State Police Reconstruction Unit, Ms. Toomey said.

Ms. Pothier was pronounced dead at the Martha’s Vineyard Hospital around 11:30 p.m. on Thursday.

Visiting hours are today from 5 to 8 p.m. at the Chapman, Cole and Gleason Funeral Home in Oak Bluffs. A funeral mass is scheduled for tomorrow at 11 a.m. at Our Lady Star of the Sea in Oak Bluffs.

West Tisbury police were dispatched at 9:59 p.m. on Thursday to the scene of the crash, approximately one mile from the entrance to the Martha’s Vineyard Airport. The fire department and tri-town EMTs also were dispatched; police from Edgartown and Oak Bluffs provided assistance.

West Tisbury police Sgt. Jeffrey (Skipper) Manter was the first to respond to the scene, and observed a young woman lying near the shoulder of the road, later identified as Ms. McCarron. A second young woman, later identified as Ms. Pothier, was pinned in the front passenger seat of the vehicle.

Both women were transported to the Martha’s Vineyard Hospital; a trauma alert was issued and a request made to scramble the Med Flight emergency hospital. However the hospital was advised the helicopter was not operating due to the foggy weather, and officials instead contacted the U.S. Coast Guard who immediately dispatched a boat.

Chief Toomey said it is too soon to tell if the foggy conditions played a role in the accident.

With high school graduation ceremonies scheduled for Sunday, the Vineyard community was grief-stricken over the accident all weekend. Expressions of sympathy from readers poured into the Gazette Web site, which carried news of the accident on Friday.

Ms. Pothier was a 2008 graduate of the high school. Ms. McCarron graduated at Sunday’s ceremonies but did not attend; her mother and sister appeared on stage to accept her diploma. High school principal Stephen Nixon acknowledged the tragedy while addressing the 2009 graduating class at class night at the Tabernacle on Friday.

“We as a school and a community suffered a tragic event last night . . . our hearts go out to Kelly and her family,” Mr. Nixon said.

As students and their families gathered for the traditional evening where scholarships are handed out, a get well card was circulated for Ms. McCarron. Following his brief statement and before the ceremony began, Mr. Nixon called for a moment of silence.

Vineyard schools superintendent Dr. James H. Weiss said yesterday that it had been an emotional weekend for students and staff. He said school administrators and guidance staff assembled at 5:30 a.m. Friday to discuss the accident and plan a response.

He said they considered the possibility of postponing class night and graduation ceremonies, but in the end decided against it.

“We decided the best thing to do was move forward the best we could. We thought it might be therapeutic for many of our youngsters and many of the adults, too,” he said.

Mr. Weiss said spoken or unspoken, the accident clearly was on everyone’s mind.

“It might have been more of a factor on Friday then Sunday. First because so little time had passed; and second because we give away so many memorial scholarships at class night, sometimes to honor the memory of other young people we have lost,” he said.

He said grief counselors were available to students and staff on Friday and will continue to be available through this week and for as long as needed.

“Anybody who needs help during this period should know we have people ready to meet with them,” the superintendent said.