Truck carrying fireworks catches fire and explodes in Tennessee

No one injured in incident, volunteer fire department says, and it is not known how truck caught fire

Firefighters in Tennessee had to respond to an unexpectedly early Fourth of July scene after a truck caught fire on a major highway and its load of fireworks went off, triggering a spectacular display.

Video of the scene on Interstate 75 in the community of Ooltewah showed a huge cloud of sparks and rockets emerging from a trailer that the truck was hauling, as a stunned crowd watched from an overpass.