CARROLLTON, Ky. (AP) -- Kentucky State Police say two pre-school-aged children were pronounced dead at the scene of an overturned school bus on a narrow country road in northern Kentucky.

Trooper Brad Arterburn said the bus carrying nine children headed home from a Head Start pre-school program Monday, flipped onto its side and struck a tree.

He said four children were taken to hospitals and three were released to their parents.

The driver of the bus escaped unharmed.

An adult aide on the bus was taken to a hospital.