A commercial vehicle on fire blocked Interstate 75 south at mile 151 in Campbell County, according to the Tennessee Department of Transportation.

All lanes reopened around 4:30 a.m. Tuesday morning.

Around the time of the incident Monday night, one lane southbound reopened around 11 p.m. to allow drivers through but traffic was still backed up for nearly 10 miles -- reaching the Tennessee/Kentucky line.

"This is a significant fire with possible hazmat," Mark Nagi, Community Relations Officer for TDOT Region 1, tweeted Monday night.

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TDOT didn't expect the scene to be cleared until 6 a.m on Tuesday. The fire was reported at 7:08 p.m. Monday. Northbound traffic is not affected.

Shortly after the fire was reported, viewers started posting photos to the WBIR Facebook page of what may be coming from the scene.