Through four years of junior ROTC training at Mar Vista High School in Imperial Beach, James Treber led his team against much larger foes in physical fitness contests – and won every single match. “He worked the kids really, really hard, but in a way that they loved him,” said his JROTC instructor, John Strait, 58, of San Diego. “He worked hard, a fantastic work ethic.”

That Treber, 24, was so strong and agile made it all the more shocking when his JROTC friends and teammates learned that the Green Beret had died Sunday in Afghanistan when a Humvee rolled over into a canal.

“I couldn't believe it,” said Cpl. Rafael Navarrete, 22, a Camp Pendleton Marine and close friend of Treber's since their days as JROTC teammates at Mar Vista High. “He's always been physically capable of doing anything. I figured he'd be able to get out of any situation.”

Treber was born in Hawaii, the son of a career Navy sailor. He always liked sports, said his brother, Gordon Treber, 25, of San Diego, but he found his niche in JROTC, a high school program in which students exercise, drill and wear uniforms.

“That was kind of a steppingstone for him,” his brother said.

Hector Roman battled Treber in the physical fitness contests as his fierce competitor and, at the same time, his best friend. Their personal stats in events such as pull-ups, sit-ups, the long jump and the 1.5-mile run wound up almost even.

“We were basically tied, but he scored higher by sliding on his butt in the long jump,” Roman, 24, said, laughing at the memory. “I guess he won.”

As team captain, Treber placed in the top six nationally in the Youth Physical Fitness competition during his senior year in 2002.

A high school apprenticeship program landed him a slot in the merchant marine straight out of high school. Friends said he made good money aboard a Navy cargo ship but spent most of his time away from home.

“He was tired of traveling, for the most part,” Navarrete said. “(He wanted) to be with his friends and family.”

Treber worked for a while at a Vons supermarket in Imperial Beach. Three years ago, he decided to join the Army. Friends said the choice was sudden but not surprising.

“You could always tell he wanted to join the military,” said Billy Schultz, 23, of San Diego, a JROTC buddy who stayed in close touch with him.

Treber joined the Army's demanding Special Forces unit – the famous Green Berets – and rocketed up the ranks, achieving the rank of sergeant in just 2½ years. He wound up with the 1st Battalion, 7th Special Forces Group, at Fort Bragg, N.C.

He married a year ago. On Treber's MySpace page, he and wife Tamila are shown hugging at the beach.

“He told me he was so happy he met her,” said Ana Roman, 25, of Vista, Hector Roman's sister and a longtime friend of Treber's. “He said it was the best decision that he'd made.”

Treber had arrived in Afghanistan six weeks ago for his first combat deployment, in a dangerous area near Kandahar. Strait heard from another former JROTC student who happened to be riding in the same convoy that the Humvee overturned on a night mission. Treber and two other soldiers drowned; only one escaped.

“He was just a really, really fine young man, doing what he wanted to do,” Strait, a retired Navy master chief, said tearfully.

Besides his brother, Treber is survived by his wife, of Fayetteville, N.C.; his mother, Laurie Treber of Fort Mohave, Ariz.; his father and stepmother, Gordon and Nicole Treber of Astoria, Ore.; sisters Barbara Hunt of Orange County and Angel Hunt of Modesto; and his grandparents, Paul and Kate Treber of Colton, Ore.

Treber's family has gathered in Fayetteville. Friends said he will be buried in San Diego, but arrangements aren't yet complete.

To many of Treber's JROTC friends who now serve in the military, his death is another harsh reminder that the country is still at war.

“It really brought it back home that this is really serious,” said Amanda Mathew, 19, of Imperial Beach, a friend of Treber's who is in the Marine Corps Reserves. “It can happen to any of us.”