A crash in the Town of Chenango in which a  vehicle flew off an Interstate 81 overpass and landed on its roof on Castle Creek Road is tentatively blamed on drowsy driving.

Broome County Sheriff's offiicals say the car was traveling south on the Interstate at around 3:30 p.m. Monday when it veered toward the median. Investigators say the driver's sister shouted a warning and the driver over-corrected, sending the vehicle off the overpass to the road below.

The driver, her teenaged sister and an 11 month old child were taken to Wilson Memorial Regional Medical Center for treatment of minor injuries.

The car had North Carolina license plates.

The names of the occupants of the vehicle were not released.

The crash closed a portion of Castle Creek Road for about a half hour.