UPDATE: All lanes are back open on Interstate 75 southbound after a semi overturned early Wednesday morning..

PREVIOUS STORY: Breaking now an overturned tractor trailer on I-75 southbound at exit 20 is causing a big traffic headache in Bradley County.

The wrecker is working to pull the semi to the shoulder, but all lanes are still blocked at this time.

Channel 3 has a crew at the scene and will let viewers know when the wreck is cleared.

The cause of the wreck is not known at this time.