Authorities scrambled to pull a submerged from the waters of the Brownsville Shrimp Basin on Thursday.
A 14-year-old was rescued and rushed to the hospital, but several others remained trapped inside the vehicle.
It is not clear how the car ended up in the water or who was driving.
Authorities fear the other people inside the vehicle may be dead.
It happened at Zimco Marine off Everglade Road around 4 p.m.
Port of Brownsville Police Chief Carlos Garcia said heavy duty cranes have been working to retrieve the car from the water.
The teen was taken to Valley Regional Medical Center at her family has been notified.
Action 4 News will provide more details as updates become available.