The three-alarm fire in an industrial complex, spread quickly to the roof.
Firefighters had a hard time locating the source of the fire.
It was eventually found to be two cars that were burning inside an automotive shop.
Midland was closed for a few hours.
The fire has now been put out.
The owners of the automative parts shop say the reason for the fire may have been to cover up a robbery. They say tools and cash were stolen.