The JROTC Marine Corps cadets at Gar-Field Senior High School in Woodbridge have a clear idea of the honor and wreckage that death in combat brings.

Yesterday, in the school's main lobby, they helped dedicate a memorial to the three Gar-Field graduates who have died serving in the military: Marine Lance Cpl. Brian A. Medina, 20, and Army National Guard Spec. David Ruhren, 20, who were killed last year in Iraq, and Richard W. Yates, a naval medical corpsman killed in South Vietnam in 1969.

The cadets said the deaths -- particularly those of the two recent alumni -- are sobering. But some said they represent a sacrifice they are willing to make.

"Obviously, it scares me -- if it doesn't scare you, you're insane. But I don't know, I just feel like I should go," said Patrick Clouse, 17, of Dale City, a captain in the school's Junior Reserve Officers' Training Corps. "I decided that on September 12, 2001. I am going to join the Marines. If they decide to send me to Iraq, that's where I am going to go."

Bill Willis, a physics teacher and Vietnam War veteran, served as host of the dedication, which included students, county School Board members and the families of the fallen soldiers. "We honor each one not only as a soldier, a sailor or a Marine," he said, "but also as young men in the prime of their lives and as students from our school."

The memorial is a wooden display case containing duplicate medals and photographs of the three alumni. The dedication had the pomp of a commencement and the gravity of a funeral.

The Gar-Field symphonic band, its members dressed in tuxedos and black dresses, played "America the Beautiful," and Willis read a wrenching letter that Ruhren's mother, Sonja, wrote to her son after he died.

"Hi, handsome," the letter began. It went on, "You had no idea that the man you were trying to become, the image you were trying to become, you were already there."

Willis said he and other school officials got the idea for the memorial last year after Medina died. They raised more than $3,000 in funds and materials from the school's staff, an American Legion group, a Veterans of Foreign Wars post and local merchants.

In his own research, Willis learned about Yates and tracked down his friends by putting ads in local papers and military publications.

He even spoke with one of Yates's former classmates in Alaska who still reads a local paper and saw an ad.

One of the hardest parts of creating the memorial, Willis said, was leaving space for more names.

Many of the JROTC cadets said they were ready to take on the challenges. School officials said JROTC programs across Northern Virginia are generally becoming more popular.

In Prince William, the area's second-largest school system, enrollment in the JROTC program has increased in the past five years from about 500 students to as many as 800, said Fred Milbert, a curriculum supervisor.

Milbert said the county is hoping to add more programs at other schools in the future.

In Fairfax County, Northern Virginia's largest system, the program's enrollment for the past five years has not changed, at 880 to 890 students a year.

As Medina's and Ruhren's parents spoke, many of the JROTC cadets gazed at the podium with clenched jaws.

"This reminds us all of all the danger we're going to face. We don't know what's going to happen," said Christopher Hoffmann, 17, a junior.

As he was listening to the alumni's parents, he said, "I was thinking about how hard it would be for my parents."

Hoffmann stepped into the line of people waiting to file past the memorial.

After staring at it for several seconds, he placed a hand momentarily on the shoulder of a fellow cadet and then walked away.

Gar-Field Marine JROTC cadet Zachary Hicks, 14, left, and band member Joeff Abel view pictures of David Ruhren, 20. Dale City VFW members, Skip Griffin, left, and John Dodge attend the dedication of the memorial at Gar-Field Senior High School in Woodbridge.