Metro Fire crews responded to the Insurance Auto Auction lot on Douglas Road and found 20 vehicles on fire.
Firefighters say the cars were engulfed in flames.
A manager with Insurance Auto Auction says it is not unreasonable to think that it may have been an electrical issue with one of the cars that sparked the fire before it spread. Metro Fire has ruled out arson as a cause.
Both the fire department and company say there are security cameras on the lot but it is unknown what they captured.
Insurance Auto Auction remained open for business Monday.