Dummer resident Seth Jones, the boyfriend of the Berlin woman who died after a July 4 traffic accident on Martha’s Vineyard, died Tuesday night from injuries received in the accident, the woman’s mother said.

Jones, who was 26, never regained consciousness after the accident and died Tuesday at Beth Israel Hospital in Boston, said Paulette LaFlamme, mother of Heather LaFlamme, 21.

Heather LaFlamme died July 7 at Brigham and Women’s Hospital.

Massachusetts State Police confirmed that Jones has died and said additional information should be released later today.

LaFlamme said she’s been trying to cope with the loss of one of her two daughters, and now she has to deal with Jones’ loss.

“This is just getting worse,” she said. The two had been dating for five or six months and were vacationing with Jones’ family on Martha’s Vineyard when the accident took place, she said.

Heather had made the honors list at the University of New Hampshire, where she was studying recreational management. Jones was a welder at the Portsmouth Naval Shipyard, she said.

The two were in the backseat of a 2012 Jeep Wrangler that was southbound on Barnes Road Extension when it attempted to make a U-turn and was broadsided by a 2009 Volkswagen Tiguan traveling behind it, Massachusetts State Police said.

Jones’ parents — Thomas and Margaret Jones, both 51, of Dummer — were also hurt in the accident. Thomas Jones was driving, and investigators have noted the odd location of the steering wheel, on the right hand side of the car.

“Among the potential factors we are investigating are the speed of the Tiguan, and whether the right-side placement of the Jeep’s steering wheel affected the driver’s vision in taking a U-turn to his left,” state police said in a statement issued July 9.

LaFlamme said she’s yet to talk to the Joneses, who were also hospitalized after the accident.

“Right now, they must be devastated,” she said.