CBS News correspondent Ashley Morrison reports at least three funnels touched down in northwestern Louisiana.
Authorities said an unnamed 20-year-old driver died when his car hit a tree felled by the storms near Shreveport.
Another man was luckier, when the steeple of the First United Methodist Church in Shreveport was blown off the building, landing on his car as he was stopped at a red light.
The 57-year-old driver, Michael Williams, was seriously injured but alive in the crushed car.
CBS Affiliate KSLA correspondent Ben Wolf reports firefighters worked feverishly to save Williams.
Eyewitness John Beauregard told Wolf the falling steeple "sounded like a loud explosion." He said some onlookers were praying when they realized there was someone in a car trapped underneath.
Williams was taken to LSU Hospital with broken bones all over his body, reports Wolf, but rescue crews said the man gave them a "thumbs up" a he was pulled from the wreckage.
Emergency crews were also at the scene in Haughton, La., where more than 30 homes were damaged.
A 94-year-old woman and her 70-year-old daughter barely escaped when their home was split in half by a large falling pine tree.
The older woman ended up under a roofing beam. Fortunately, the beam didn't fall all the way to the floor. "I'm just sore, I feel pretty good," the older woman told KSLA. "I just thank God I'm as good as I am." She was treated for minor injuries.
The National Weather Service said flash flooding was likely as a major storm dumped more rain on areas already soaked by weeks of record-setting precipitation. Little Rock received a month's worth of rain - five inches - in a day.
Rain and flooding were forecast to continue over the Mississippi River on Friday as a strong front lingered over the region.
There was heavy rain and at least two tornadoes in Arkansas Thursday, but there were no reports of injuries in that state. Tree and power lines were down and roads were flooded.
First Electric Cooperation was reporting more than 84,000 customers in 17 counties with power outages this morning. Entergy Arkansas said nearly 9,000 of its customers were without power across the state this morning.
About 100 miles north in East Camden, Ark., a possible tornado caused damage to a fire training academy, catching students by surprise.
Several buildings were destroyed. A fire truck was buried under debris and several cars were damaged.
"All of our ears started to pop and it was eerily quiet for a second," student Michael Eckelkamp told CBS Affiliate KTHV correspondent Pam Baccam.
The Arkansas Department of Emergency Management said in Johnson County seven water rescues were conducted, in which between 17 to 20 people were rescued.
CBS Affiliate KTHV reports that 12 to 15 mobile homes were destroyed in east Camden. There were no injuries reported.