Oregon investigators have spoken about the explosion of a World War II vehicle that took the lives of two people while filming a video of the military tank in action for a non-profit military preservation exhibit.

Deschutes County Sheriff L. Shane Nelson said in a statement that a crew was filming the 1944-vintage M18 Hellcat tank destroyer as it fired when the blast occurred that killed Steven Todd Preston, 51, and Austin Tyler Lee, 22.

"This is a tragic day. Two families lost loved ones, and our hearts and prayers go out to them," he said. The U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives is helping the authorities in its investigation since the cause of the blast is still unknown.

Preston's close friend and co owner of the tank, Steve Greenberg said that his friend had fired rounds numerous times over the years without any issues. The accident was a great surprise to Greenberg as he said that Preston was very aware about safety.

Preston had passion with tanks, with World War II history and had been collecting memorabilia according to Dennis Ripp, president of the Military Vehicle Collectors Club of Oregon.  He added that Preston was the former president of the group and was a board member of the national Military Vehicle Preservation Association.

Ripp was devastated with his friend's death. "People would donate money and he'd give them tank rides," Ripp said. "He was a great guy, a super guy. He could help anyone with projects."

The tank was said to be from Yugoslavia which Preston bought from a dealer in Denver.

Greenberg mentioned that they and the tank were presented in the commercial for the video game "World of Tanks". He also added that Preston and another friend had begun to build a museum that exhibits historic vehicles.

Preston appeared in the 2011 reality series of Discovery Channel likewise in Smithsonian Channel series "The Weapons Hunter" which talked about rare military artifacts.

Preston owned a Portland towing company and leaves behind a wife and two children.