05/24/2012 02:57 pm ET

Jason Blackburn Finds 20 Tombstones In His Backyard (VIDEO)

Digging up a backyard can kill your back, but finding 13 tombstones are buried there could scare someone to death.

That's the grave situation that Jason Blackburn faced while doing yardwork at his home in Memphis, Tenn.

Blackburn, a nurse at the Baptist Memorial Hospital for Women in Memphis, was clearing a walkway that leads to his dog’s pen when he dug up a tombstone below some 3 inches of dirt, MSNBC reported.

At first he mistook it for a garden stone, but then had a slightly more morbid response.

"My first reaction was, 'Oh my goodness, I hope there's not dead bodies in my backyard,'" Blackburn, 35, told the Memphis Commercial Appeal. "I mean that's the first reaction when you're digging in your backyard and you find tombstones."

After searching the Internet for Pvt. Arthur Woodson, a name on one of the tombstones, Blackburn linked the grave to the Memphis National Cemetery, a historic memorial park that dates back to the Civil War and is now run by the Department of Veterans Affairs.

"All of the headstones came from Memphis National Cemetery," Raymond Miller, cemetery director of the Memphis, Little Rock and Corinth national cemeteries, told the Memphis Commercial Appeal.

A short investigation into the records at the cemetery identified all 20 tombstones as having been removed between July 5 and Dec. 28, 1970, during a period when the U.S. Army controlled the facility. The Department of Veterans Affairs took over maintenance of the cemetery in 1973.

Miller told the paper that the headstones were removed because they were replaced when another relative died and shared the gravesite.

When Blackburn bought his home last year, it was advertised as having a "beautifully landscaped yard."

"And it was," Blackburn told the paper. "It still is; minus the headstones."

There are other theories about the tombstones, according to Jack Sammons, a former city councilman, who bought the house in 1981.

"When I bought the house, the real estate broker had told me that a guy who used to live there had worked for the cemetery," Sammons told the Commercial Appeal. "I was told he would bring home the ones they messed up when they were engraving them. It's a granite marker, not like an Etch-A-Sketch, I guess. You couldn't just wipe 'em clean."

Regardless of how the gravestones got there, Miller has left no stone unturned trying to figure out the true story -- especially since the identified real headstones were all in their places at the cemetery.

"When we do a first internment, we order the headstone and then they come in and then it is set when the spouse or the veteran, whoever it might be, when we have subsequent internment," Miller told MyFoxMemphis.

By law, the initial headstones should have been smashed to pieces beyond recognition. He added the next step in this case will be verify to the families of the ones found that all is well and they can call the cemetery or come out to see for themselves.

Meanwhile, Blackburn has got a lot of holes to fill in his backyard now that the tombstones aren't there.