Dive teams were called to the Connecticut River in Middletown for a car in the water early Saturday.
Dive Teams from three departments, as well as firefighters from Middletown and Portland fire were called to River Road and Eastern Drive on reports of a car in the water.
When crews arrived on scene, they found a car fully submerged in the water.
Officials from the Middletown Fire Department say no one was in the car when crews responded.
Crews searched the area for three hours using drones, boats, and thermal imaging cameras to search for a driver.
Officials say the driver of the vehicle was not found.
Crews have since cleared the scene, and say the incident is under investigation.