UPDATE at 12:12 p.m.: One lane of traffic is open as crews continue to clean up the scene.
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Crews are on the scene of a jack-knifed truck under the Interstate 75 overpass at the I-75/I-24 split.
All lanes headed north toward Chattanooga are blocked at this time. Traffic is backed up past Cloud Springs Road, according to TDOT. Southbound traffic is not affected.