A school bus carrying teenage campers rolled over on a winding Idaho highway Friday afternoon, injuring 11 people, the Idaho State Police said.

Seven of those hurt had critical injuries and four had non-critical injuries, according to an ISP news release. The Boise County Coroner’s office had not received any reports of fatalities as of 5:45 p.m., coroner’s investigator Noah Webster said.

The bus was carrying about 30 campers and staff back to Boise from the Treasure Valley YMCA’s camp at Horsethief Reservoir. All of the teens on the bus were between 13 and 18 years old, according to ISP. They were all taken to area hospitals to be checked out, the ISP said.

The Valley County Sheriff’s Office said they were notified of the crash about 3 p.m., and several law enforcement and emergency medical agencies responded.

St. Luke’s Health System was caring for multiple patients at its Boise and Meridian hospitals and was “working to reunite families,” said spokesperson Taylor Reeves Marschner.

Treasure Valley YMCA President and CEO David Duro said later Friday that it had been a very challenging afternoon but that all the campers, both on the bus that crashed and on a bus that was behind it, had made it back to the Boise area. The Sunday to Friday overnight camp session had just ended and he said riding the bus is normally a great part of the experience for campers.

“It’s one of those experiences that every child should be able to enjoy safely and I don’t know what happened,” he said. “All we’ve been told is that it’s under investigation.”

The YMCA camp where children can engage in canoeing, archery, zip-lining and other outdoor activities opened in 2010 and is about 35 miles north of the crash site. The popular camp runs multiple sessions throughout the summer for kids between 2nd and 11th grades, and the YMCA frequently runs several buses full of kids to and from each session.

Another session is set to begin on Sunday. Duro said officials are now determining whether to hold it as scheduled. He said families always have the option of driving their children to camp instead of taking the bus.

“It’s the first time we’ve ever had something like this and we hope it’s the last time,” he said about the crash, adding that they’ll be awaiting any reports to review and see what can be done to make the journey safer.

The YMCA contracts with Caldwell Transportation to take kids on school buses to and from the camp, he said, adding that the company also transports many students to area schools throughout the school year. No one answered the phone at the company’s Boise location on Friday evening.

The crash blocked both lanes of Highway 55 for hours. The two-lane road is one of the state’s two major north-south routes, and it is frequently packed with weekend travelers headed from the Boise region to the vacation destination of McCall and popular area campsites.