The bus, carrying Waggener High School students and adults, lost control on I-64 in Shelby County Tuesday afternoon.
It was returning from a visit to Eastern Kentucky University when it suddenly swerved across three lanes and crashed into a concrete barrier.
Investigators said the front left tire was the cause of that collision.
Injuries that included broken bones were reported for 35 people aboard the bus.
State police said they’re looking at inspection records and bus violations that happened prior to the crash. They said they’ll also be checking for any previous violations and annual inspection records.