A school bus and a tractor-trailer collided in rural southern Nebraska, killing two students and two drivers, the Nebraska State Patrol said Thursday.

At least five more children were transported to hospitals after the fiery crash at a rural intersection near Blue Hill around 5 p.m. Wednesday, the patrol said.

The driver of the truck, 21-year-old Travis Witte of Blue Hill, and the driver of the bus, 59-year-old Marla Wentworth of Red Cloud, died in the crash. Two students also were killed: 18-year-old Dustin Tesdahl and 10-year-old Caroline Thallman, both students at Blue Hill Community Schools.

Five other students were taken to area hospitals. Two children, a 7-year-old boy and 6-year-old girl, were treated and released Wednesday. Two others, a 10-year old boy and an 8-year old girl, were admitted to a hospital in Hastings and were in stable condition.

A 7-year old girl was flown to Children's Hospital in Omaha, where she was in serious condition.

All of the injured students attend Blue Hill Community Schools as well. The district serves students in kindergarten through 12th grade.

Authorities have released no details about how the crash occurred.

Witte's mother, Penny Witte, said Thursday that he was hauling bales of hay for the family farm when the fatal incident happened.

"He had a big heart," she said.

She added that her son, a one-time high school football star who played defensive end for the 2008 C-2 state championship Blue Hill team, was engaged to be married at the time of the crash.

"Our first concern is for the families of those affected by Wednesday's events," Webster County Attorney Sara Bockstadter said in a statement issued through the State Patrol. "Our hearts go out to everyone who has been touched by this tragedy. We ask for your consideration as our communities begin to process what has happened and work toward healing."

Bockstadter did not return several messages left Thursday by The Associated Press seeking more details of the crash.

The sheriff's office referred questions about the crash to Bockstadter.