(EAST BATON ROUGE, La.) -- Louisiana authorities are investigating at least four deaths that are possibly linked to the massive storm that swept across the state Monday.
The East Baton Rouge Sheriff's Office reported that 33-year-old Justin Blaine Thompson was found in a vehicle submerged in water under a Baton Rouge overpass.
Across the Mississippi River, 40-year-old Alvarado Morentes Hermelindo died and another person was missing after their car crashed Monday evening, according to Louisiana State Police.
Officials also reported two other deaths likely linked to power outages.
Lake Charles, Louisiana, saw close to 18 inches of rain in 24 hours, according to the National Weather Service. The region is still recovering from last year's hurricane season and deadly freeze in February.
"Ladies and gentlemen, what happened yesterday was the third heaviest rain event in the city of Lake Charles' history," Lake Charles Mayor Nic Hunter said during a news conference Tuesday.
Hunter added that Lake Charles has declared four federal disasters over the course of a year.
Interstate 10, near Baton Rouge, was closed due to flash flooding and many drivers were forced to abandon their vehicles. Some cars were completely submerged.
Gov. John Bel Edwards said various state agencies had conducted hundreds of water rescues, including people trapped in cars and in homes.
The storm system is also impacting eastern and central Texas. Storm preparations are underway in Houston, according to officials.
More than 20 tornadoes have already been reported from Louisiana to New Mexico. As of Tuesday evening, there is a tornado watch in east Texas.