School Bus Crash in Mississippi Kills 3

Emergency personnel work the scene of a head-on collision between a school bus and an 18-wheeler in Calhoun County, Miss. (AP)

A head-on collision between a school bus and an 18-wheeler leaves debris on the highway. (AP)

In this aerial image taken from video provided by WMC-TV, the scene of a head-on collision between a school bus and an 18-wheeler. (AP)

An aerial image taken from video provided by WMC-TV, the scene of a head-on collision. Students were on their way back from a career event in Oxford, Miss. (AP)

Emergency personnel work the scene of a head-on collision between a school bus and an 18-wheeler in Calhoun County, Miss. (AP)