The business, on Gratiot in Marysville near the Port Huron city line, is fully engulfed in flames.
Authorities have closed Gratiot Boulevard and have begun evacuating nearby homes and businesses.
Firefighters from Marysville, Port Huron and Port Huron Township are on the scene.
Black smoke is visible for miles and the sound of explosions is rattling windows in downtown Port Huron.
Firefighters are in a defensive posture, working to keep the fire from spreading from the plant filled with tanks of flammable and explosive gases. Firefighters are worried about a lack of hydrant water pressure in the area.
The response on this incident was enormous! I expected something about ten times the size. Considering the hazmat threat, it's good they were able to get it under control.