Nobody was hurt in the fire.
Crews say it started when a construction crew dropped sparks onto cardboard and other packing materials in the warehouse.
Fire crews were called to the Morton Salt Plant in Manistee a little after 10 this morning, and are still on scene to make sure the fire is completely out.
Four fire crews worked through the afternoon, pulling out materials from the plant and containing the fire.
As you can see from the video, the roof is badly damaged but how the fire affected the rest of the warehouse is still unknown.
A fire this size demanded a lot from the firefighters, and that was at the forefront of their minds as they tried to contain the flames.
9&10's Eric Lloyd and photojournalist Jared Barraco were on the scene of the fire and have more details.