The accident occurred on Interstate 55 in St. John the Baptist Parish, near New Orleans, amid low visibility caused by a combination of wildfire smoke and fog.
One of the vehicles involved was a tanker truck cnewarrying a hazardous liquid, which caught fire and compromised the tank. Police said they may find more fatalities once they remove the tanker and access the vehicles near it.
One vehicle also plunged into the water, but the driver was rescued safely.
Some of the injured were taken to hospitals by ambulance, while others sought medical attention on their own.
The highway was closed for more than 24 hours as emergency crews worked to clear the wreckage and repair the damaged bridge. (ILKHA)