Five words buckled Neal Dillon's knees on Dec. 11, 2006: We regret to inform you.

When Marine casualty officers came to his door that cold Monday night, Mr. Dillon said he fell in their arms before they even mentioned his son's name.

"Before they could finish, I asked, 'Is our boy dead?' " Mr. Dillon said at his Aiken home. "They said yes and stayed with us for hours, but my wife and I didn't say anything for a while."

Their son, Cpl. Matthew Dillon, 25, was killed when his Humvee was hit by an improvised explosive device in Al Khalidiyah, Iraq.

His mother, Lucy Dillon, replayed the last conversation with her son the night earlier again and again in her head.

As always, Cpl. Dillon was looking out for his fellow Marines. He asked his mom to bake Christmas cookies and fruitcake, which he didn't care for, so his bunkmates would have a treat for the holidays.

"He was so excited about the holidays and coming home," she said.

Iraq had become a second home for the young Marine. He was on his second tour.

Cpl. Dillon was struck by an IED and received his first Purple Heart during his first tour in 2003. Having been born in a military family, serving his country came natural. He participated in ROTC while attending Augusta State University. In his junior year, he became the Dillons' third son, behind his older brothers Robert and Michael, to join the military.

"I believe 9/11 really made him feel he had an obligation to go to the military," Mr. Dillon said.

He became a military policeman. He also trained for six months to become an emergency medical technician, mainly to help his comrades.

"When he was first wounded, there was no one there to treat his wounds. He also saw that happen to other guys," Mrs. Dillon said. "He never wanted that to happen to a Marine again."

His valor and service have been honored with Aiken County's Corporal Matthew V. Dillon Scholarship Award for outstanding JROTC cadets; the Corporal Matthew V. Dillon Leadership Award, presented to outstanding military police school graduates; and the Corporal Matthew Vincent Dillon Memorial Chapter, created by local Purple Heart recipients.

"We know this is what he would have wanted to do," Mr. Dillon said. "He was all about helping people."