Two children were pronounced dead at the scene of a bus crash Monday afternoon in Carroll County, Ky., not far from the scene of a 1988 bus crash that killed 24 children and three adults.Three children were flown by helicopter to Kosair Children's Hospital and one child and an adult were flown to the University of Kentucky Medical Center, state police said. Three children were examined at the scene and released to their parents; the driver was uninjured.The bus left Boone Road, partially overturned and hit a tree, state police said. Investigators do not yet know why the bus left the roadway, state police said. Authorities were dispatched at about 4:30 p.m.Kosair Children's Hospital chief nursing officer Cis Gruebbel said the three children — ages 3, 4 and 5 —suffered broken bones and head injuries, and at least two will treated in the critical care unit.Carrollton was also the site of a school bus crash in 1988 that killed 24 children and three adults. That bus was being used for a church activity and was returning after a day at an amusement park when it was hit head-on by a drunken driver. It remains the nation's deadliest drunken-driving collision.