Oregon authorities are still searching for answers Wednesday morning as to what caused an explosion inside a World War-II era tank that left two people dead.

The blast occurred Tuesday afternoon at a public gun range east of Bend.

Paramedics tried to save the victims but they died from their injuries. No names have been released.

"This is a tragic day," Sheriff Shane Nelson told KTVZ. "Two families lost loved ones, and our hearts and prayers go out to those that lost loved ones today."

Nelson said rescuers were able to speak with one of the victims before death.

"One of the victims was still alive, and they were able to speak with that victim," Nelson said. "Bend Fire Department did attempt life-saving efforts on that victim, but the victim died."

There was no word on what caused the explosion, but Nelson says video was being shot around when the blast occurred that could help investigators learn more about what happened.

"There was a camera crew on scene, and they were filming the tank," Nelson said. "As to what they were filming or why they were filming, those details haven't been found out yet."

Authorities said there is no risk to the public.

"The Oregon State Police made sure this scene was safe for their investigators and our investigators," Nelson said.

Detectives from the sheriff's office and the Oregon State Police Arson and Explosives Section are investigating.

The Associated Press contributed to this report.