(CBS) — More than a dozen people were hurt after a Megabus bound for Chicago rolled over south of Indianapolis in Greenwood early Tuesday morning. The bus was traveling from Atlanta.

The crash occurred at around 4:30 a.m. One person was taken to the hospital in critical condition, four others had moderate injures and 14 had minor injuries, according to the Greenwood Fire Department.

Police believe the driver of the bus may have swerved to avoid a different crash on I-65 and that the wet roads may have played a role in the crash. One vehicle involved in the earlier crash was in the road, forcing oncoming traffic out of that lane. Indiana State Police say the bus driver swerved and then overcorrected and the bus tipped over on its side in the median.

Craig Steichen of St. Charles was on the Megabus. He runs a non-profit called “Operation Warrior Wishes” and was returning from a tour of NFL stadiums. He says he was asleep when it happened.

“All I remember is a thud and then rolling around about four or five times hoping to say when is this going to stop,” Steichen said. “I had no idea I would get hit in the head with something or whatever and I didn’t. The guy next to me was sitting up unfortunately he was pretty bloodied up.”

Steichen says police arrived almost immediately.

Sean Hughes, Associate Director of Corporate Affairs, Coach USA North America in a statement, “We will be providing assistance and support for all of our customers involved in this incident Safety is our absolute priority and we are assisting the authorities with their investigation into the circumstances of the incident.”

All lanes are back open after being shut down for several hours.