Colleton County Fire-Rescue Chief Barry McRoy tells WCIV-TV the crash happened early Sunday on Interstate 95 in the state's southeast. He says the bus was carrying about 30 students and adult chaperones back to North Carolina from Orlando. The chorus is from Beddingfield High School in Wilson.
McRoy said the bus heading northbound ran off the left side, crossed southbound lanes and went down an embankment.
McRoy said two suffered serious injuries, including the driver. Nine others were taken to the hospital by paramedics, and six more arrived later for treatment.
The Beddingfield Chorus Facebook account said all students and chaperones treated at the hospital "should be fine."