KOTV.com -- OKLAHOMA CITY (AP) A 21-year-old Marine from Oklahoma City died in Iraq when the vehicle he was riding in hit a roadside bomb just 12 days before he was scheduled to return home, military officials said Monday.

Lance Cpl. Trevor A. Roberts died Saturday while conducting combat operations in Al Anbar province, the Defense Department said.

Roberts, who was assigned to Marine Forces Reserve's 2nd Battalion, 14th Marine Regiment, 4th Marine Division, was in the right rear passenger seat at 8 p.m. when the explosion occurred, said 1st Sgt. Scott Baker, a spokesman for Roberts' unit. Another person riding in the vehicle suffered a minor concussion.

Baker said Roberts was one of 30 people from the unit who volunteered to go to Iraq and had been in that country for seven months. The unit has since been activated and is training at Fort Sill, preparing for a July deployment.

"He was an All-American boy," Baker said. "He was brought up in a good Christian family. "He was a good Marine. He volunteered to go. He felt it was his obligation to serve God, the country and the Corps."

Roberts was trained as an artillery specialist.

Rob Olmstead, pastor of Eagle Heights Church in Oklahoma City, said Roberts wanted to study anthropology or sociology in college.

"His experiences in Iraq were pretty amazing ...," said Olmstead, who was Roberts' pastor. "He was always aware of culture and slow to judge it and more open to learning from it."

His parents, Chuck and Twyla Roberts, had spoken to him two days before he was killed, Baker said. Roberts is also survived by a brother, who is attending college.

Baker said Roberts was the first Marine from the unit killed in the war.

He said Roberts was very involved in his church and was planning to participate in a church mission to China this summer.

Roberts graduated from Westmoore High School in 2004 and attended Oklahoma City Community College, Oklahoma City radio station KTOK reported.