Tour bus headed to Masters overturns, driver charged with DUI: Officials The accident happened during rush hour in Columbia County.

A tour bus headed to the Masters Tournament overturned this morning, leaving one person in critical condition and the driver charged with driving under the influence, according to Georgia State Patrol and Doctors Hospital.

The crash happened at 8:45 a.m. on an interstate in Columbia County, Georgia, as the bus was en route to the golf tournament in nearby Augusta.

The bus first ran off the right side of the road, and the driver then overcorrected to the left, causing the bus to turn over in the median, the state patrol said.

Eighteen passengers traveling from Atlanta were on board, the state patrol said.

Nine victims were taken to Doctors Hospital in Augusta; one person is in critical condition, one victim is in serious condition, and one patient is in fair condition, the hospital said.

Another 10 victims were transported to Augusta University Hospital, where five are still in serious condition, a spokesperson said.

The others have been treated and released.

"Some of the witnesses that were on the bus at the time, they said that this had happened on two occasions previously from their trip to Atlanta -- where the driver had gone off the right side of the roadway and brought it back onto the lanes," Georgia State Patrol Sgt. Chris Wright told ABC affiliate WJBF in Augusta.

The driver, 61-year-old Steven Hoppenbrouwer, of Gwinnett County, Georgia, was charged with DUI and failure to maintain lane, according to the state patrol.

Investigators believe Hoppenbrouwer was using drugs, the state patrol said.

ABC News' Rachel Humphries contributed to this report.