Indiana State Police said an off-duty trooper saw the semi-trailer smoking heavily from its rear axle at about 5:40 p.m. on I-65 near the 209 mile marker, about 6 miles south of the Rensselaer exit in Jasper County.
The trooper crossed over on I-65 to stop the semi on the shoulder, and the fire was spreading from the brakes to the trailer, police said.
The driver was able to disconnect from the trailer, which was hauling 38,000 pounds of frozen bagels, police said.
The fire department was able to extinguish the blaze and the right lane of I-65 was closed until about 1 a.m. Monday to clean the debris, police said.