SAN DIEGO - One of the key components used by ground forces in Afghanistan is on hold -- an order from the Pentagon after a deadly training accident in Nevada that killed eight Marines during a 60mm mortar team live fire exercise.

"There are usually three in the team -- a leader, an assistant team leader and an ammo man," said Richard Gilbert, a combat-tested Marine who was a team leader with a mortar team in Fallujah, Iraq.  

Firing a mortar is fairly automatic, Gilbert said. Coordinates are entered into the tripod, the shell is dropped into the tube and a firing pin shoots it out.  

There is a suspicion in the training accident involving Marines from Camp Lejeune that the shell exploded while in the tube.  

"I have fired hundreds of rounds, in training and in combat, from high explosives to illumination rounds to white phosphorous, and I've never had a system do that," Gilbert said. "We've been using this system since Vietnam and there's never been a problem like this."  

It's why the Pentagon suspended all 60mm rounds, not just the explosive ones, until investigators determine what happened.  

"Again, I've never heard of this happening, but I hope I never hear of it happening again," Gilbert said.