(KMOV.com) -- A school bus went up in flames Wednesday morning in north St. Louis.
The bus, owned by First Student, was returning to the depot on Interstate 70 after making its run when the driver noticed the flames in the back of the bus.
The driver pulled off onto West Florissant to put the fire out. No students were on the bus at the time.
Firefighters say that a heater on the bus appears to be the cause for the fire.