A 6-year-old boy who collapsed on a Harrison County school bus Thursday died from an abscess where two teeth had been removed from his lower jaw, county coroner Gary Hargrove said.

Alexander “Alex” Callender, a kindergartner at Lizana Elementary, went into shock from the infection and his body shut down, Hargrove said after Friday’s autopsy. Callender collapsed on the bus after leaving school Thursday.

Callender lived in a rural area near Pass Christian.

Grief counselors were available to speak with students at Lizana Elementary Friday.