A school bus carrying about 30 passengers overturned on Idaho Highway 55 north of Banks on Friday afternoon. Eleven passengers were injured – seven of them seriously – and a section of the road was closed for nearly four hours, according to a press release from the Idaho State Police.

According to ISP, troopers responded to the crash near mile marker 84 around 3 p.m. The Treasure Valley YMCA summer camp bus had people ages 13 to 18 on board, and all children were airlifted or airlifted to local hospitals, the release said. According to ITD, Idaho 55 was reopened from mile markers 79 to 97, Banks to Smiths Ferry, around 6:45 p.m.

The bus was one of four summer camp buses, and all other buses were not involved in the crash, state police said. YMCA and police officials are continuing to update the family. State police spokesman Aaron Snell told the Statesman that the bus was heading back to Boise from the YMCA camp at Horsethief Reservoir, which is about 10 miles from Cascade.

“This was a tragic end to an otherwise great week-long summer camp,” David Duro, president and CEO of the Idaho YMCA, told the Idaho Statesman by phone.

Duro said there were several adults on the bus, including camp counselors and the bus driver, who is not employed by the YMCA.

Another bus was traveling behind the crashed bus, Duro said, causing delays in the return trip to Boise. However, the children have now been reunited with their families. He added that the YMCA is committed to providing families with all the resources they need and that staff are visiting hospitals.

“All of these participants are truly part of the YMCA family, so it is very important to us,” Duro said.

Mark Snider, spokesman for Saint Alphonsus Health System, told the Statesman by phone that the regional hospital in Boise had admitted seven minor patients, all of whom were not in critical condition. He added that Saint Al's Eagle and Nampa hospitals were on standby to accept patients.

Shortly after 4:30 p.m., doctors at St. Luke's also received a call that there had been a “mass casualty incident.” They requested as many doctors as possible to come to emergency rooms in Boise and Meridian, according to text messages obtained by the Statesman. According to the text messages, all victims of the bus crash arrived at local hospitals by 6:21 p.m. St. Luke's spokesman Taylor Reeves Marschner told the Statesman by email that the health system had “multiple patients” at its hospitals in Boise and Meridian and was working to reunite families.

It is not known whether another vehicle was involved in the accident.

Multiple agencies, including the Eagle and Gem County fire departments, as well as the Boise County and Ada County sheriff's offices and emergency services, responded to the scene.

Spokeswoman Angie Heuring said ITD did not yet have any information about the cause of the crash.

Statesman contributor Hayat Norimine, Daniel Ramirez and Noble Brigham contributed.