What started as a good and refreshing day trip for the Yolo Middle School children, turned quickly into a nightmare, as two buses collided at the end of a line of vehicles stopped along Highway 120. 12 children and a parent were injured.

One bus rear-ended the other just before 11 a.m. Thursday, about a mile from Yosemite Valley, said park spokesman Scott Gediman.

The victims were taken in ambulances to clinics and hospitals in Merced, Modesto and Yosemite Valley to be treated for minor to moderate back and neck injuries, Gediman said.

The rest of the children who were not hurt were transported to the valley to wait for new buses to return them to Newman, said Rick Fauss, Superintendent of Newman-Crows Landing Unified School District.

“They were 10 minutes into the park, and the whole string of cars came to a stop faster than they anticipated and the driver wasn't able to stop fast enough. Our main responsibility has been to notify the families so they know where their kids are being taken,” added Fauss, according to The Associated Press.

It is not yet known what the cause of the accident was and highway officials have already begun towing the damaged busses and are clearing the scene.