(CNN) -- One person was killed and as many as two dozen were injured Thursday when a commercial bus crashed into an overpass pillar on a southern Illinois interstate, authorities said.
The Megabus coach line said there was one fatality, a woman, among the 81 ticketed passengers aboard its Chicago-to-St. Louis bus. The wreck happened on southbound Interstate 55 near Litchfield, about 55 miles northeast of St. Louis, the Illinois State Police told CNN.
Illinois State Police identified the victim as 25-year-old Aditi Avhad of India.
"The thoughts and prayers of our entire staff go out to everyone involved, particularly the family of the person who has died," the company said in a statement.
The injured were being taken to hospitals in Litchfield and nearby Staunton. Paula Endress, a spokeswoman for St. Francis Hospital in Litchfield, said the 13 patients taken there had injuries ranging from minor to grave. And Susan Campbell, chief executive of Staunton's Community Memorial Hospital, said that facility had taken in three patients and expected as many as nine more.
The bus driver was among the injured, but his injuries were not believed to be life-threatening, Megabus said.
The uninjured passengers were taken to the Litchfield Community Center, and Megabus said arrangements were being made to get them to their destinations.
The cause of the crash was under investigation, police said.
CNN's Rich Porter and Amanda Watts contributed to this report.