The bus overturned after colliding with a Jeep Wrangler, whose driver was pronounced dead on the scene.
A Jeep Cherokee was also involved in the crash, Lake County Sheriff Mark Curran said in a press conference.
The bus was carrying kindergarten through fifth grade students to Newport Elementary School.
Twenty-three of the children were taken to the hospital for treatment of minor injuries by another school bus, accompanied by paramedics. The other 11, with more serious injuries, were transported in ambulances.
Based on witness accounts, the bus "may have been late on the light," Lake County Sheriff Mark Curran said. The driver did not suffer serious injuries.
More images from the scene:
