A sheriff says a student was killed and 12 people were injured Thursday when a school bus and a dump truck crashed along a curve on a winding road in northern Kentucky.

Pendleton County Sheriff Craig Peoples confirms that it was a student who died in the crash but did not immediately release a name.

Twelve people, mostly children, were treated at St. Elizabeth Medical Center in nearby Grant County and released.

The collision occurred shortly after 7 a.m. on Highway 22 in Pendleton County, a rural farmland area about 40 miles south of Cincinnati.

State police did not release details about what caused the crash.

Sheriff Craig Peoples said the wreck happened on a curvy stretch of highway.

"It is a very crooked road," Peoples said. "We have a lot of motorcycle accidents. We have dump trucks turn over at least once a year."

Although he did not give details on how the crash happened, he said the dump truck was hauling stones from a quarry and flipped over, losing its load on the highway. He said the bus had extensive damage on its driver's side.

Four hours after the crash, the bus sat in a yard along the road. All the windows from a center door on the driver's side had been ripped out and the roof was dented.

Peoples said 11 elementary, middle and high school students were on the bus when the crash happened. He said the drivers of both vehicles will undergo drug and alcohol screening, which is standard procedure.