Arlington National Cemetery says a Louisiana National Guardsman who was killed in a helicopter crash in the Gulf of Mexico can't be buried at the hallowed grounds because he was killed during a training exercise.

The burial plots are only for service members who die on active duty and space is limited, the cemetery says.

Staff Sgt. Thomas Florich, 26, was among four guardsmen and seven Marines killed when Black Hawk helicopter crashed March 10 off of Florida.

His father, a former Army major and Green Beret, calls the burial rejection "a slap in the face."

"My son died in uniform and deserved to be buried at Arlington," said Stephen Florich, of King George, Virginia, which is about 45 miles south of Arlington Cemetery.

Stephen Florich, who resigned his Army commission when his wife died, said he has received support from military veterans and government leaders in his fight to get his son buried at Arlington. Some veterans have told him they would give up their own spot in the cemetery for Thomas Florich.

"I'm overwhelmed by the support my family and I have received from across the country," he said.

In a statement, the Army said, "Staff Sgt. Florich's death was tragic, and a deep loss to his family, the Army and our nation.

"His record of service makes him eligible for inurnment, so he may be forever enshrined in Arlington National Cemetery; however, since at the time of his death he was on active duty for training only, he therefore does not meet the well-established criteria for interment in Arlington National Cemetery."

The problem is space.

Cemetery spokeswoman Jennifer Lynch said Arlington is expected to run out of burial space in about 40 years, meaning "those currently serving on active duty may not have an opportunity to be buried at Arlington National Cemetery, if they retire after a life of service."

"This is not including any conflicts that may arise in the next 40 years," Lynch said.

Col. Pete Schneider, spokesman for the Louisiana National Guard, said he was disappointed in the cemetery's decision. An appeal was filed with the secretary of the Army seeking an exception.

As of Wednesday, there had been no reply.

U.S. Rep. Charles W. Boustany Jr., a Louisiana Republican, said he also asked for an exception. While Thomas Florich may not have been on active duty, Boustany said, he "was supporting active duty Marines when the training accident occurred."