A Kane'ohe-based unit lost its second serviceman in three days when a Marine was killed Thursday during combat operations in Afghanistan.

Marine Pfc. Matthew L. Bertolino, 20, was a passenger in a vehicle that overturned during a patrol near Jalalabad, Afghanistan. He was thrown from the truck and died from his injuries, his mother said yesterday.

Bertolino was assigned to the 1st Battalion, 3rd Marine Regiment, out of Marine Corps Base Hawai'i.

His mother, Joyce Bertolino, said she last saw him at home in Hampstead, N.H., over Christmas, when he was given three weeks leave before being deployed last month to Afghanistan.

She said details were sketchy, but Department of Defense officials didn't indicate whether the vehicle was under attack when it overturned.

The death is being investigated.

On Tuesday, a Navy hospital corpsman assigned to the Kane'ohe Marines died after being shot in the chest. Petty Officer 3rd Class John T. Fralish, 30, of New Kingstown, Pa., on a patrol northwest of Methar Lam in Laghman province, Afghanistan.

The unit suffered its first combat fatality Jan. 27 when Marine Lance Cpl. Billy D. Brixey, 21, of Ferriday, La., died of injuries from a roadside bomb.

Bertolino, Fralish and Brixey departed from Hawai'i in January with a contingent of 900 Marines and sailors for seven-month deployment.

Bertolino had worked in carpentry before joining the Marine Corps in January 2005.

His mother said he felt compelled to enlist, despite her misgivings.

"He was very proud to become a Marine. He felt a duty to enlist," she said.

"It changed him immensely. ... He was just more mature, more confident, more proud."

Afghanistan's mountainous landscape and small villages reminded him of Italy, his mother said.

Bertolino had enlisted for four years, then hoped to train to become a police officer in New Hampshire, his mother said.

"He wanted to build a home when he came out," she said.

Funeral plans have not been completed. Bertolino's body likely will arrive in the U.S. on Monday or Tuesday, his mother said.

In addition to his mother, Bertolino is survived by his father, Stanley Bertolino, and by two older sisters, Kristin and Kimberly.

"He was loved by everyone," said his mother.

"He was too young."