Eric Royster was driving his 18-wheel vehicle on Interstate 20 in Harrison County, East Texas, when it went up in flames.
When he stepped out onto the highway to inspect the damage, he was mowed down and killed by a car coming the other way.
Officers then arrived on the scene and inspected the burnt truck and discovered the stacks of cash.
Authorities believe that around $700,000 was destroyed while $300,000 remained in tact.
There is still no confirmation as to what caused the fire and police are now looking for leads as to where the money came from and where it was going.
Harrison County Sheriff's Office Lieutenant Jay Webb told KTLV: 'It was not money that was being transported as part of the owner's money or furniture.'
'This department, the county and the country would love to find out who's receiving the money. Where it's going. What was it going to be used for.
Atlas Van Lines, who own the vehicle that was burned, released a statement to KSLA saying: 'This is an incredibly tragic accident, and we're deeply saddened to hear that Eric Royster lost his life ... We are investigating this incident, and will continue to look into it as evidence becomes available.'
The undamaged money was reportedly sent to a federal reserve bank in Dallas.
