SCHUYLKILL COUNTY, Pa. (WBRE/WYOU) — More than 30 people were injured in a crash in Schuylkill County involving a bus that was packed with high school girls returning from a church retreat.

Three people remained in critical condition Monday night as Pennsylvania State Police continued efforts to determine what led to the crash.

The coach bus carried 31 teenage girls and volunteers from a Lancaster County church retreat when it crashed Sunday afternoon.

According to a statement from LCBC Church Manheim, they were traveling from Lake Champion, New York, just over two hours from the crash site off Interstate 81 in Frailey Township, Schuylkill County.

The bus was one of three traveling together.

“This bus, in particular, was the middle of the three buses and just for unknown reasons, at this time, it just kind of veered off,” said Pennsylvania State Police Trooper David Beohm.

The bus left the roadway, hitting an exit sign and dragging it 300 to 500 feet, and then kept driving. Finally, the bus drove through the grass and crossed the exit ramp. It continued across Route 25, breaking a guide rail before it went 50 feet into the woods.

Bus parts remain trapped in the trees.

“There are 32 injured from the crash, three of whom are in critical condition,” said Trooper Beohm.

State police say five people were flown to area hospitals. The driver, Adam Wright, 37, from Lancaster, suffered serious injuries. He was conscious at the scene and transported to a Geisinger area hospital, where he remained hospitalized Monday evening.

Wright worked for Premiere #1 Limousine Service.

“The troopers earlier today went up to the hospital to talk to the driver of the bus to help us figure out what was going on,” said Trooper Beohm.

Officials hadn’t released any additional information Monday evening. This is an active investigation.

State police ask anyone who may have been an eyewitness to the crash to contact PSP Frackville.

The church released a statement on its website that reads, in part:

“Thank you for praying for those involved in today’s bus accident involving 31 students and leaders from our Manheim Campus who were returning from the LCBC HSM (high school ministry) retreat at Lake Champion in New York. We ask that you would continue to pray for each student and their families during this very difficult time.”

As of the most recent update on LCBC’s website Monday afternoon, 18 of the 31 students and volunteer leaders had been released from the hospital, leaving 13 passengers and Wright still hospitalized.