Police say a truck driver “presumably fell asleep” after crashing through a barrier wall in a wreck that ejected the driver and shut down the highway.

The accident happened on Monday, July 9th at around 5:30 a.m. in Cobb County, Georgia. According to WSBTV News, the unnamed truck driver was hauling scrap metal in his rig along Interstate 75 when it initially hit a guardrail and scraped along a barrier wall for about a quarter mile before knocking over a metal guardrail and crashing through a large concrete sound barrier wall.

The force of the impact overturned the big rig, began a small fire, and ejected the driver, critically injuring him, and he was rushed to a nearby hospital in critical condition. “The driver presumably fell asleep, causing him to drift off the road,” said Cobb County police spokeswoman Officer Sarah O’Hara in a statement. The crash forced the closure of the northbound lanes of I-75 just north of Wade Green Road for the duration of rush hour. Drivers used Highway 74, Interstate 575 north, and Highway 92 as alternate routes, but the northbound lanes of I-75 were reopened at around 11:00 a.m.

The incident is still under investigation and the current health condition of the unnamed driver is not known. It is not clear if he will be cited for the incident.