(WVLT) - A portion of I-75 in Loudon County is closed because of a sinkhole. The sinkhole opened up at about 10:30pm Tuesday night near on I-75 at Exit 68. The entire northbound side is shut down. Drivers must get off at Exit 68 on Highway 11 and then get back on at Exit 72. TDOT has worked all night to repair the hole and expect the road to be opened back up again by 6:00am. TDOT says sinkholes are very common in that part of the county and it was most likely caused by the weekend rain.