RAW VIDEO: 14 injured after Chicago-bound Megabus crash on I-65

GREENWOOD, Ind. (WLS) -- Authorities say 14 people were injured after a Megabus heading to Chicago from Atlanta overturned on northbound I-65 near Indianapolis.

State police said the bus flipped on its side just before 5 a.m. Tuesday in Greenwood, Ind. Investigators said the driver may have swerved to avoid another crash.

One woman, who may have been pinned under the bus, was in critical condition.

There were 50-60 people on board, according to state police.

Craig Steichen, of St. Charles, Ill., was sleeping on the bus at the time of the crash. He said several people had serious bumps and bruises. He also said it was raining for nearly the entire trip from Atlanta.

"Once we hit the truck, we started rolling over," said Steichen. "I moved three or four different times thinking, when is this going to stop?"

The accident initially shut down I-65 in both directions just south of Exit 99, for Greenwood Main Street, according to the Indiana Department of Transportation. But traffic was getting through in both directions with come lane closures around 6 a.m., as crews worked to clear the scene.

The manifest for the Megabus said it made stops in Chattanooga, Tenn., Nashville, Tenn. and Louisville, Ky.

State police said weather was likely a factor in the crash. There were storms in the area overnight and roads were slick.

reenwood Fire Department Battalion Chief Chris Harrell said about 35 uninjured passengers were being taken by a city bus to a nearby hospital as a precaution and to regroup.

The northbound bus became entangled in the median's cable barrier in the southern Indianapolis suburb of Greenwood.

The Associated Press contributed to this report.