Benton County Coroner Larry Hobson says the official cause of death of the bus driver is "sudden cardiac death."
Hobson says the driver "clutched his chest and slumped over," according to the students on the bus.
Hobson and MHP Captain Poulos both ID'd the bus driver as William Chester Cole.
Cole was 63 years old. No autopsy will be performed, according to Hobson.
Some of the injured children were flown to a hospital, the Mississippi Highway Patrol said.
Doctors said at least eight students were hurt and four of them are in serious condition.
They said the other four children are expected to be released from Le Bonheur Children's Hospital today.