Four Indiana High School students were on their way to a three-day event with a district school orchestra when their school bus crashed into the back of a stopped tanker truck Wednesday afternoon.

After the incident at the intersection of Route 422 and Bonniebrook Road in Summit Township, the students were taken to Butler Memorial Hospital in a private vehicle.

“They were all evaluated at the hospital and released,” said Dale Kirsch, superintendent of the Indiana School District.

He said three of those students continued to Hickory High School in Hermitage, where the event sponsored by the Pennsylvania Music Educators Association (PMEA) was taking place. The other student decided to go home.

PMEA is a music education nonprofit organization that forms bands and orchestras from student musicians across several school districts.

The drivers of both vehicles were taken to hospitals.

The bus driver, Daniel C. Funk, 67, of Sharon, Mercer County, was taken to Allegheny General Hospital by medical helicopter after being extricated from his vehicle.

He remained in critical condition Thursday, a spokesman at the hospital said.

Jeff Finfrock, general manager with the STA bus company, the bus subcontractor that Indiana School District uses, said he’s glad the students on the bus were OK.

“We’re certainly glad that none of the students were injured. Our thoughts and prayers are obviously with our employee,” he said.

Finfrock declined to give further information about Funk, citing the investigation with state police.

The driver of the rig, Dave C. Waichter, 61, of St. Clements, Ontario, was taken to Butler Memorial with unknown injuries.

The truck is from the Safely-Kleen company of Breslau, Ontario.