A Tripler Army Medical Center soldier who was killed along with 16 others Saturday by a suicide car bomber in Kabul, Afghanistan, had volunteered to go on what was his first combat deployment, officials said.

Staff Sgt. Christopher R. Newman, 26, of Shelby, N.C., was among at least 12 Americans killed when a driver ran his vehicle into a "Rhino," an armored bus, in the Afghan capital and detonated explosives, the Pentagon said.

Newman arrived in Hawaii on Nov. 1, 2007, and was assigned as a behavioral health specialist at Tripler. He volunteered to deploy in June with the 528th Combat Operational Stress Control Medical Detachment out of Fort Bragg, N.C., and served as a prevention team noncommissioned officer in charge at Camp Marmal in Afghanistan, Tripler said in a news release.

Jan Clark, a Tripler spokeswoman, said to the best of officials’ knowledge, Newman is the first Tripler soldier to die in combat during the war.

Newman was raised by his grandparents in Shelby, N.C., and joined the Army after graduating from high school in June 2004, Tripler said.

He served more than two years as a behavioral health specialist at Brooke Army Medical Center at Fort Sam Houston in San Antonio before coming to Hawaii.

The Fox News affiliate in Charlotte, N.C., reported that Brent Newman thought his older brother’s 6-foot-6, 280-pound build would make him invincible in Afghanistan.

"I’m thinking, just that right there, he ain’t getting killed," Newman said.

The Charlotte Observer said Christopher Newman helped run a psychiatric ward in Afghanistan and counseled other soldiers.

"All he wanted to do in his life was help other people out," Brent Newman told the newspaper. "And that’s what he died doing. He was helping people out."

The Rhino vehicle he was in was on its way to a hospital, the family was told.

Newman is survived by wife Amanda, who lives in Texas, and a 5-year-old daughter from a previous relationship, the newspaper said.

The Pentagon said at least 12 Americans were killed in the blast, which the Taliban took credit for, but officials said the total had not been finalized.