NASHVILLE, Tenn. - Officials in Nashville braced for more deaths Monday as the flooded Cumberland River continued to swell, sending muddy water rushing through neighborhoods and threatening the historic heart of Music City after a destructive line of weekend storms killed 21 people in Tennessee, Mississippi and Kentucky.

Using motor boats and canoes, authorities and volunteers rescued scores of residents trapped in flooded homes, some which looked like islands surround by dark river water. The downtown - home of a historic warehouse district that dates back to the 1800s and is now occupied by bars and restaurants - was nearly deserted after authorities evacuated residents and tourists. Floodwater spilled into some streets near the riverfront, and restaurants and bars in the warehouse district were closed. A few blocks away, the historic Ryman Auditorium, longtime former home of the Grand Ole Opry, was in no immediate danger.

"It's shocking to see it this way, but it was an incredible storm," Mayor Karl Dean said as he surveyed the downtown flooding. The Cumberland River was expected to crest Monday afternoon at 11 feet above flood stage, and officials worried they may find more bodies in the rising floodwaters.

Thousands of people took refuge in emergency shelters, including about 1,500 guests at the Gaylord Opryland Resort and Convention Center who spent the night at a high school to escape the flooding. The resort's hotel, located northeast of downtown along the river, had "significant water" inside and would remain closed indefinitely, said hotel spokeswoman Kim Keelor.

German tourists Gerdi and Kurt Bauerle, both 70, said resort staff suddenly started rushing people out of the area Sunday night.

"We had just finished eating and suddenly they said: 'Go! Go! Go!'" said Gerdi Bauerle, who was visiting from Munich. "And we said 'Wait, we haven't even paid.'"

Water flooded parking lots around the nearby Grand Ole Opry House and the Opry Mills shopping mall, but it wasn't immediately clear if water had made it inside the buildings.

On the west side of Nashville, flood waters backed up from the Harpeth River had submerged hundreds of homes in the Bellevue suburb.

Lisa Blackmon, 45, stood on a street at edge of flood waters that swamped her neighborhood Monday. She had no flood insurance, and she lost her job at a trucking company last December. She feared she had nothing left in her home.

"I know God doesn't give us more than we can take," she said. "But I'm at my breaking point."

Across from downtown on the east side of the river, LP Field, where the Tennessee Titans play also was threatened. Water covered one parking lot near the river but had not reached the stadium on Monday afternoon. At the Wild Horse Saloon, a popular country music hangout on the downtown riverfront, there was water in the loading dock area and the bottom floor.

The Cumberland flooded quickly after the weekend's storms dumped more than 13 inches of rain in Nashville over two days. That nearly doubled the previous record of 6.68 inches of rain that fell in the wake of Hurricane Fredrick in 1979.

"That is an astonishing amount of rain in a 24- or 36-hour period," Tennessee Gov. Phil Bredesen said Sunday.

The storms, which also spawned deadly tornadoes, killed at least 12 people in Tennessee, six in Mississippi and three in Kentucky.

Eleven in Tennessee drowned, including at least six in Nashville, and one was killed by a tornado in western Tennessee.

Three of the people killed in Mississippi died when high winds believed to be tornados hit their homes; the other three were killed in what authorities said were weather-related traffic accidents. Three weather-related deaths were also reported in Kentucky, including one man whose truck ran off the road on Sunday into a flooded creek.

The weekend deaths came on the heels of a tornado in Arkansas that killed a woman and injured about two dozen people Friday. A week ago, 10 people were killed by a tornado from a separate storm in western Mississippi.

Bredesen said officials hoped for the best, but knew there might be more deaths reported Monday as authorities got their first real look at the damage after a weekend filled with frantic rescues.

"This is going to go on for a while," Bredesen said. "It's going to take a while for the water to recede and us to get down into this. It's going to take several days for this to get back to anything near normal."

The Cumberland River already reached record levels since an early 1960s flood control project was put in place. With so much water inundating its tributaries, it was difficult to gauge whether the river would stop at 50 feet deep, or 11 feet above flood stage.

Much of the damage from flooding was done in outlying areas of Nashville and across the middle and western parts of Tennessee. Rescues turned dramatic with homeowners plucked off roofs and pregnant women airlifted off a waterlogged interstate.

The rain ended Monday but there will likely be weeks of cleanup for residents and public works employees alike. Though there was no official estimate, it was clear thousands of homes had been damaged or destroyed by flooding and tornados.

Emily Petro, with the Red Cross in Nashville, said the agency was sheltering about 2,000 people across Tennessee - about 1,200 of them in Nashville.

Hospitals, schools and state buildings also were flooded. Most schools in middle Tennessee would be closed Monday and most universities in the Nashville area postponed final exams, though many state workers were expected to return to their jobs, if possible.

The state's roads also were in bad shape. The three major interstates in the Nashville area were closed over the weekend and Interstate 40, which runs east to west through the state, would likely remain closed since standing water is still stranding drivers.

Bredesen said more than 150 roads were closed in middle Tennessee alone with washouts and bridge damage destruction fairly common. The Cumberland could add millions of dollars to the damage total. Officials in Kentucky said more than 300 roads were blocked by flood waters there.

Officials in Tennessee said Sunday the flooding is as bad as they've seen since 1975 when water memorably inundated the old Opryland amusement park east of downtown Nashville. Even the state's own emergency operations center wasn't immune. It took up to a foot of water below a false floor, forcing officials to relocate to an auxiliary command center.

"I've never seen it this high," said emergency official Donnie Smith, who's lived in Nashville 45 years. "I'm sure that it's rained this hard at one time, but never for this much of an extended period."