PHOENIX — A man is dead after he drove his car off the 24th Street overpass on I-10 and hitting a bus Thursday night, authorities say.

A DPS trooper on the scene tells 12 News a witness reported what happened and when officers arrived, they found a vehicle smashed into a bus under the I-10 along Sky Harbor Circle. Unfortunately, there were no witnesses on the scene at that time.

It’s still unclear whether the driver of the city bus was injured and whether any other people were on the bus when the car flew off the freeway.

Troopers are looking at multiple factors right now, including speed and whether impairment may have played a role. Sky Harbor Circle road is typically used for airport shuttles and rental car returns so it doesn’t look like it’s going to cause any major back ups this morning, but it will impact traffic near the airport.

DPS is investigating the crash. No word on why or how the man drove on the overpass.