UPDATE: Nov. 18 at 6:30 a.m. Scott County Dispatch has confirmed with LEX 18 that I-75 northbound is back open following an explosion near mile marker 136 on Sunday night. No other details about the incident have been released. Original Story: The Scott County Sheriff's Office posted on social media that parts of I-75 northbound are closed due to an explosion.The area around mile marker 136 on I-75 is closed. The sheriff's office estimates that part of the highway will be closed for two to four hours.LEX 18 will continue to make updates.