Police in Southern California have arrested a school bus driver over the death of an autistic teen who died after he was left alone in the vehicle for up to seven hours on a sweltering day.

Whittier police arrested 37-year-old Armando Ramirez at his Apple Valley home on Wednesday. He remains jailed Thursday and it's unclear whether he has an attorney.

He could face a charge of dependent abuse.

Authorities say 19-year-old Hun Joon Lee was found unresponsive aboard the bus in the Los Angeles suburb last Sept. 11, when temperatures soared to 100 degrees.

A wrongful death lawsuit by the family alleges that employees of the Pupil Transportation Cooperative failed to do a required sweep of the bus before leaving it locked at a depot.