In Mississippi, one person was killed in Scott County and at least one other was injured in Grenada County in storm-related incidents across the state, emergency managers reported Wednesday afternoon.

A Flash Flood Emergency was issued for the city of New Orleans as part of a deadly severe weather outbreak that caused numerous thunderstorms and even tornadoes across the lower Mississippi Valley and Gulf Coast.

Life-threatening flooding occurred Wednesday afternoon in the New Orleans metro area as several inches of rain drenched the city in just hours, sometimes falling at a rate of 1-3 inches per hour.

Emergency management reported numerous roads and underpasses in and around New Orleans were underwater and impassible from the late morning into the afternoon.

Dramatic videos showed first responders working to block off flooded roads to prevent vehicles from driving on them and getting submerged.

"It is very difficult to maneuver around New Orleans this afternoon," said FOX Weather's Robert Ray as he drove along flooded streets in the city.

In addition to the torrential rains, damaging wind gusts blew through the city. The National Weather Service in New Orleans has reported thunderstorm wind gusts of up to 71 mph at a fire station just east of the city and a gust of 78 mph on the Lake Ponchatrain Causeway. A tree fell onto a home in Pearl River, Louisiana.

New Orleans received over 6 inches of rainfall in about seven hours, with La Place, Louisiana, reporting at least 10 inches.

Tornado strikes Slidell, Louisiana

Just to the north of town in Slidell, crews were picking up debris after an apparent tornado swept through a neighborhood.

Slidell police captured video of the aftermath of the severe storm, showcasing damaged storefronts and vehicles, scattered storm debris and fallen power lines along U.S. Route 11. The officer providing commentary in the video below describes the damage to one building as "catastrophic."

"Basically, every apartment was full at the time," one first responder said in the video. "I guess at least 50 people were in there. People's doors were shut because the railings came in. The whole roof came out. So, we had to get women and children out."

Local government officials said hundreds of homes and businesses in the immediate region received some sort of damage, with over 100,000 electrical outages.

To the west of New Orleans, St. Landry Parish emergency managers reported four people were injured when a tree fell on a car. One injury was reported as critical and the victim was being flown to a hospital in Baton Rouge.

Storm death reported in Mississippi

Meanwhile, in Mississippi, one person was killed in Scott County and at least one other was injured in Grenada County in storm-related incidents across the state, emergency managers reported Wednesday afternoon.

At least 72 homes have suffered storm damage across several counties, emergency officials said, including 45 in Scott County. Three homes were damaged near where the person was injured in Grenada County.

Emergency officials are also closely monitoring a potential levee break near a subdivision on Highway 16 in Yazoo County, Mississippi. All residents in the area have been evacuated for their safety.

Brief tornado wreaks havoc near Houston

On Wednesday morning, tornado damage was reported in southeastern Texas.

Preliminary estimates suggest the damage in Katy, Texas, was caused by an EF-1 tornado with a brief track and estimated maximum winds of 90 mph, according to a storm survey conducted by the NWS.

"If it was a tornado, it dropped down right in the middle of this parking lot of this strip center and went away," FOX 26 Houston Reporter Shelby Rose said. "I mean, there is no damage anywhere surrounding us. Not even to some small trees."

While there were no people inside that building at the time, there were people inside a sports bar that also received damage.

The National Weather Service in Houston is continuing to survey the damage in the Katy area to determine if the EF-1 estimate is the final determination for the twister's rating.

Flash flooding in Texas leads to harrowing rescues

Another Flash Flood Emergency was posted Wednesday morning in Kirbyille and Newton in southeastern Texas, where over 8 inches of rain fell in just 24 hours.

Due to flooding, all major roads into Kirbyville, Texas, were closed Wednesday morning. Multiple fire departments deployed from around the region are conducting rescue efforts in the area.

A dramatic video recorded by the Roganville Volunteer Fire Department in Jasper County, Texas, showed the cab of the fire truck filled with water after the first responders said they rescued a man from a submerged vehicle.

"We just did a water rescue," the firefighter said in the video. "You can barely see the taillights of the car that we picked this young man out of. Needless to say, he was a little bit shaken up."

The firefighter then pans the video and shows how high the water was at the time, which was covering the tailpipe of the truck.

"Sad to say, but we're stuck in the ditch," the firefighter said in the video. "We're waiting on a front-end loader to push us out so we can continue doing our water rescues."

While the firefighters are waiting for help to get pushed out of the ditch, the firefighter keeps rolling as he gets back into the truck, and the water is seen to be so high that its up to their laps.