BATON ROUGE (CNN) -- Jessica May escaped New Orleans days before Hurricane Katrina in August 2005 and made a new life in Baton Rouge, Louisiana. All was going well until one month ago, she said, when her home went up in flames.
After the fire, she and her partner, Denard Singleton, moved with their six kids, ages 4 to 10, into Singleton's parents' home in Denham Springs.
Then, on August 13, she had to flee again -- this time, from the Amite River, which rose so quickly she had virtually no time to prepare.
Neighbors "were banging on the door at 6 o'clock in the morning," May said. "We walked out, and you could see the water rising."
She and her family waited about an hour for a rescue boat.
"I was scared," May said. "I was like, 'How are we going to get out of this?'"
An 'unprecedented' deluge
May and her family were among tens of thousands of people forced to abandon their homes and virtually all their belongings.
Some didn't escape in time. At least eight people have died in the flooding, Louisiana Gov. John Bel Edwards said Tuesday.
Officials from various parishes had put the death toll Monday night at nine, including some swept away in cars on flooded streets. The reason for the conflicting death tolls was not immediately clear.
Because this flooding was not spawned by a named storm or hurricane, Edwards called the deluge "historic" and "unprecedented."
More than 20 inches of rain have pummeled Baton Rouge since last week, and more is on the way, forecasters said. Scattered showers and thunderstorms are expected to continue through the week.
Rescuing 20,000 people
The Coast Guard and other first responders scrambled to rescue more than 20,000 people and 1,000 pets.
Civilians also doubled as rescuers. David Phung pulled a woman and her dog from her car after it had plunged underwater.
May and her family were among those rescued. After getting ferried away on a boat, she said, they walked on a flooded interstate in hopes of finding drier ground.
"Good God the water wasn't high" on the interstate, she said. "My kids were able to walk through the water."
At least 40,000 homes have sustained at least some damage, Edwards said. And many residents don't have flood insurance.
"We are going to need volunteers to get mud out of homes," Edwards said Tuesday. "Not everyone can do this on their own."
Officials asked anyone interested in volunteering to visit VolunteerLouisiana.gov to learn how they can help.
Disaster areas declared
Edwards said he expects to have close to 30 parishes -- almost half of the state's 64 parishes -- declared disaster areas
So far, President Barack Obama has granted the governor's request for an emergency declaration in 12 parishes, Edwards said Tuesday.
The Louisiana National Guard has mobilized 1,700 soldiers to help with search and rescue efforts, and military police are assisting local law enforcement with security.
But search efforts and security aren't the only concerns.
"We're going to have standing water all over south Louisiana," the governor said. "We're going to have more than our share of mosquitoes. And with the Zika threat, we need assistance to spray for mosquitoes and for mosquito control and abatement. That is made available to us as a result of the declaration."
The Centers for Disease Control and Prevention's Ben Beard said experts will be monitoring the situation, but generally, the agency is not concerned about floods triggering the spread of the Zika virus. Mosquitoes that transmit diseases are killed by the same rains that cause the flooding, experts say. Large rain events can actually reduce the number of disease-transmitting mosquitoes.
'She just breaks down and cries'
Neighbors Brad Jacobs and Erik Lang surveyed the mess caused by floodwaters surrounding their homes. Shoes, children's toys and household items floated through knee-deep water.
"We're praying it stops where it is," said Kelly's neighbor, Jenny Ragland, whose home on a ridge was spared similar damage.
Neighbor Toni Denova just bought new furniture, but she's not worried about it. All she wants is to preserve her family photographs against the rising floodwater.
"I have a boxful of pictures in my garage that I hope get saved. That's all I really care about," she said.
May, who fled to an emergency shelter with her six children, has no idea what to expect when she gets home. She's just trying to help her kids cope.
"My oldest, she just breaks down and cries," she said. "But I'm there with her to let her know everything's going to be OK."
Rosa Flores, Boris Sanchez and Kevin Conlon reported from Baton Rouge; Emanuella Grinberg and Holly Yan wrote from Atlanta. CNN's Thom Patterson, Joe Sutton and Keith Allen contributed to this report.