The deadly storm system that wreaked havoc on Louisiana, where more than 20,000 had to be rescued, is working its way into the Midwest, where officials are bracing for major flooding.

Six people have died in Louisiana, the state registrar for vital records, Devin George, told reporters Monday. George said the deaths included two people in East Baton Rouge Parish, two in St. Helena Parish and two in Tangipahoa Parish.

The storm system moved west into Texas before pivoting northeast, prompting flood warnings in southern Illinois after five inches of rain fell on the region.

Rivers in the Baton Rouge area have started to fall, but still remained above flood stage after setting record levels over the weekend, the National Weather Service said Monday.

"The rivers and streams north of Interstate 12 have crested and have started to drop, while those south of the interstate continue to rise," meteorologist Mike Efferson said.

Adding insult to injury, it started raining in Baton Rouge again Monday and the city could see up to a half-inch of precipitation.

In high-water vehicles, boats and helicopters, emergency crews hurried to rescue scores of south Louisiana residents as the governor warned that it was not over.

From the air homes in southwest Louisiana looked more like little islands surrounded by flooded fields. Farmland was covered, streets descended into impassable pools of water, shopping centers were inundated with only roofs of cars peeking above the water.

From the ground it was just as catastrophic.

Drivers tried to navigate treacherous roads where the water lapped at the side or covered the asphalt in a running stream. Abandoned cars were pushed to the side of the road, lawn furniture and children's toys floating through the waters.

"It was an absolute act of God. We're talking about places that have literally never flooded before," said Anthony "Ace" Cox in an interview with the Associated Press, who started a Facebook group to help collect information about where people were stranded. He was in Baton Rouge to help his parents and grandparents, who got flooded out.

"Everybody got caught off guard," he said.

The low pressure system that wreaked such havoc moved into Texas, but the National Weather Service warned that there's still danger of fresh floods, as swollen rivers drain toward the Gulf of Mexico.

Most of the rivers have crested, but several are still rising.

Gov. John Bel Edwards said late Sunday that more than 10,000 people are in shelters and more than 20,000 people have been rescued across south Louisiana. The Baton Rouge River Center, a major events location in the capital city's downtown, was to be opened Sunday as a shelter to handle the large numbers of evacuees.

The federal government declared a major disaster in the state, specifically in the parishes of Tangipahoa, St. Helena, East Baton Rouge and Livingston. Edwards said President Obama called him and said that "the people of south Louisiana are in his thoughts and prayers and the federal government will be a solid partner."

Edwards called on people to refrain from going out to "sightsee" even as the weather gets better.

The evacuees included the governor and his family, who were forced to leave the Governor's Mansion when chest-high water filled the basement and electricity was shut off.

Authorities worked throughout Sunday to rescue people from cars stranded on a miles-long stretch of Interstate 12 until the governor said on Twitter late in the day that everyone had been rescued.

One of those stranded motorists was Alex Cobb of Baton Rouge, who spent the night on the interstate before being rescued by a National Guard truck.

She was on her way to a bridal shower she was supposed to host Saturday when flooding closed off the highway.

She said she had food intended for the bridal shower and a produce truck about a ¼ mile up the road shared its stock with drivers — giving out fruits and vegetables to people.

The Louisiana State Police started allowing people to reclaim cars left behind on a portion of Interstate 12. Vehicles that were out of gas, stalled or unclaimed were being towed Monday to the shoulder to help clear the interstate.

Hundreds of people were gathered at Celtic Media Centre in Baton Rouge, some coming in by bus and others by helicopter.

Matthew and Rachel Fitzpatrick, from Brandon, Mississippi, hopped off one of the choppers with her grandparents. The couple had been visiting family in Baton Rouge when the flooding started. They found temporary refuge at Hebron Baptist Church but became trapped by floodwaters Saturday night.

People at the church used boats and big trucks to rescue others and bring them to the church, where helicopters started picking them up and flying them to safety Sunday.

Matthew, 29, said between 250 and 300 people were still at the church as of late afternoon Sunday. Water was creeping up to the back of the sanctuary, and they didn't have any food or water there.

"Everybody is just tired and nervous and wanting to see what kind of damage they have to their home," Rachel said.

Steele said the flooding that started Friday has damaged more than 1,000 homes in East Baton Rouge Parish, more than 1,000 homes in Livingston Parish, and hundreds more in other areas, including St. Helena and Tangipahoa parishes.

Gov. Edwards declared a state of emergency Saturday, calling the floods "unprecedented" and "historic." He and his family were even forced to leave the Governor's Mansion when chest-high water filled the basement and electricity was shut off.

In one dramatic rescue Saturday, two men on a boat pulled a woman from a car almost completely underwater, according to video by WAFB. The woman, who's not initially visible on camera, yells from inside the car: "Oh my god, I'm drowning."

One of the rescuers, David Phung, jumps into the brown water and pulls the woman to safety. She pleads with Phung to get her dog, but he can't find it. After several seconds, Phung takes a deep breath, goes underwater and resurfaces — with the small dog.

As of Sunday morning, some 5,050 people were staying in parish and Red Cross shelters, said Department of Children & Family Services Secretary Marketa Garner Walters. Even more people were staying in private shelters like churches.

Other effects from the flooding:

— A hospital in Baton Rouge — Ochsner Medical Center in Baton Rouge's O'Neal campus — has evacuated about 40 patients and is expected to evacuate another 10-15.

— Severe weather damaged AT&T Wireless's equipment and halted service for some customers in the Baton Rouge area.

— Amtrak is busing customers from Jackson, Mississippi to New Orleans instead of using the train.

— Rescuers have taken out hundreds of pets as they go door-to-door searching for people. Lt. Davis Madere from the Louisiana Dept. of Wildlife and Fisheries said he and his teams have rescued at least 100 pets since they started working Friday.

— The head of the Mississippi Emergency Management Agency says 56 people remain in a shelter because their homes are flooded.

Around Baton Rouge, worried family members tried to locate relatives. Wayne Muse, 68, ran into a police roadblock on Sunday morning in east Baton Rouge, where rapidly rising water is flooding neighborhoods near the juncture of the swollen Amite and Comite rivers.

Muse said he has been trying in vain to reach or contact his 86-year-old mother since Saturday night, when she told him by phone that she had two inches of water inside her retirement home apartment.

"She said they were going to evacuate them but no one could get to them," Muse said.

The Associated Press contributed to this report.