Traffic was backed up Thursday just after 11:15 a.m. along the northbound lanes of Interstate 69, at about the 20 mile marker for a fully involved semi fire.

It was not immediately clear what caused the fire. It began in the engine compartment. The driver of the truck got out and tried to put it out with a fire extinguisher but could not.

The semi was hauling scrap metal. It wasn’t long before the entire truck was fully involved.

Michigan State Police shut down the both lanes northbound.

Traffic was re-routed to Jonesville Road to Old 27 and back onto the interstate near mile marker 23.

Coldwater Fire Department responded with mutual aid assistance from Tekonsha.

No one was injured.