UPDATE: A bus fire on Interstate 24 near Monteagle slowed traffic on the Labor Day holiday. The highway has been re-opened to traffic.

About 40 U.S. Marines from Marine Corps Base Camp Lejeune in Jacksonville, North Carolina were aboard the bus. They were on their way to Nashville to celebrate Marine Week.

Investigators believe the bus overheated and caught fire near mile marker 136, though the cause of the fire has not been confirmed.

Troopers say the captain, who was driving bus, noticed a fire sparking from the engine, and immediately pulled over in the emergency lane, so everyone could escape what eventually grew into massive flames.

The Monteagle Fire Department was able to put the fire out in about 30 minutes.

No one was hurt, and no other cars were damaged.

The Marines were taken to a city park in Monteagle shortly after the fire, where the fire department hosted a fundraiser, but also provided lunch to the marines while they waited for a new bus.

Though their journey was delayed, the Marines did make it to Nashville.