WILMINGTON, North Carolina—Tropical Storm Florence has claimed at least 11 lives in two days as it lumbers across the Carolinas, forcing millions to flee as rivers threaten to overflow.

Florence weakened slightly Saturday, but authorities warned residents not to let their guard down because walls of rain and storm surges are expected to thrash the region for several days.

Up to 32 inches of rain had fallen in some places, according to the National Weather Service.

“Avoid complacency. A lot of people think that since this storm has been downgraded… they don’t have much to worry about,” North Carolina Gov. Roy Cooper said.

“We don’t want people to think this is over, because it’s not. It’s not over anywhere,” he said.

Mandatory evacuations and dramatic water rescues were the backdrop of increasingly grim news—a climbing death toll and environmental concerns.

Ten of the reported deaths were in North Carolina:

In Duplin County, the sheriff reported that three died when flash floods overtook their vehicles.

A house fire in Cumberland County killed a married couple.

In Lenoir County, two elderly men died—one by electrocution and one when he fell while checking on his pets.

An 81-year-old man in Wayne County died after falling while trying to evacuate.

A mother and her 7-month-old baby were killed when a tree smashed into their home in Wilmington on Friday.

A Pender County woman died of a heart attack after downed trees stopped emergency worker from getting to her.

In South Carolina, the first storm-related death was a 61-year-old woman, Amber Dawn Lee, whose vehicle hit a downed tree in the road near the town of Union, Union County Coroner William Holcombe told local news station WYFF-4.

Meanwhile Duke Energy in North Carolina reported that the rain triggered a collapse of a coal ash landfill at its Sutton Power Plant. It was unclear if the ash—which contains toxins but is deemed non-hazardous by the federal government—might have gotten into the Cape Fear River.

On Saturday night, authorities in several North Carolina communities issued a last-minute plea to residents to leave the area amid rising river waters. With at least 12 hours of non-stop rain expected along the coast, residents in Cumberland County were told “the worst is yet to come.” Fayetteville Mayor Mitch Colvin told residents to notify their next of kin if they refuse to leave the area because “loss of life is very, very possible.”

At least one North Carolina town was also forced to impose a curfew on residents due to looting. Authorities in Wilmington announced a 5 p.m. to 6 a.m. curfew starting Saturday after video appeared to capture a crowd of people looting a Family Dollar store.

The anticipated flooding in the days to come adds to a trail of destruction already left behind.

Many residents of Wilmington, one of the communities hit hardest, were forced to stay at home rather than risk running into downed power lines or tree limbs on the roads.

Keem Grady, a resident who stayed holed up in a brewery in downtown Wilmington during the storm, told The Daily Beast he had ventured out to the local Waffle House for food, hopeful after the restaurant chain, which has become a key barometer for storm recovery, had promised to open as quickly as possible. But he found only the lights out and a massive tree limb blocking the door, he said.

After two days without power, a Wilmington grocery store opened its doors Saturday morning to find mobs of people waiting outside and eager to get in, according to the News & Observer. At least 500 soaking wet shoppers had gotten into a line outside the Harris Teeter store, and employees had to warn the crowd that police would be called if any fighting broke out during the mad dash to get inside.

Jacksonville residents reportedly woke up to see deer swimming through the flooded streets, while submerged vehicles were also spotted in several areas.

In New Bern, Florence’s roaring floodwaters uprooted and swept away several bear statues that the city is known for. The statues had been bolted down into the ground.

By Saturday morning, with Florence packing winds of 50 mph as it moves through South Carolina, nearly 1 million people were without power in North and South Carolina.

While the storm has weakened, authorities in both states are bracing for “catastrophic” flooding as heavy rains cause rivers to rise and overflow. Residents in some parts of North Carolina have reportedly been isolated after roadways were completely flooded.

Weather forecasters say flooding will likely continue for days to come, with 40 inches of rain seen in some parts of South and North Carolina. The National Hurricane Center said Saturday that it expects “flooding miles and miles inland.”

North Carolina residents who stayed behind to wait out the storm have described a terrifying situation as emergency crews struggle to reach them. Annazette Riley-Cromartie, a woman who stayed in her eastern North Carolina home with her husband and three children, told CNN she and her family were forced into an upstairs bedroom by rapidly rising floodwater.

She said she heard her neighbors screaming desperately for help but even 911 was unable to get to the scene right away. “It's the worst feeling in the world to hear people yelling for help, and you can't do anything,” she said. Volunteer rescuers eventually arrived with a boat to save the neighbors, she said.

Animal rescues were also underway as the downpour continued. More than 100 animals were rescued from the flooded Carteret County Humane Society in North Carolina late Friday, leaving local authorities in search of kind souls to adopt dozens of animals.

One little kitten in New Bern also managed to captivate the internet Saturday after photos of it soaking wet and clinging to its owner in a rescue boat went viral. Robert Simmons Jr., the kitten's owner, told the News & Observer he'd been through other hurricanes before but the aftermath of Florence is “the worst it’s ever been.” With the kitten tucked away in the hood of his jacket and timidly peeking its head out, Simmons said the tiny animal's name was Survivor.