MEMPHIS, Tennessee (Reuters) – Memphis area residents were warned on Saturday that the Mississippi River was gradually starting to "wrap its arms" around the city and rise to record levels as flooding moves south.

"It's a pretty day here, and people get a false sense of security," said Steve Shular, public affairs officer for the Shelby County Office of Preparedness. "The mighty Mississippi is starting to wrap its arms around us here in Memphis."

Nearly 3,000 properties are expected to be threatened. Rising water flooded 25 mobile homes in north Memphis Saturday morning. There were 367 people in shelters in Shelby County Saturday.

"Our community is facing what could be a large-scale disaster," said Shelby County Mayor Mark H. Luttrell, Jr., in a statement.

Water has covered Riverside Drive and is creeping up Beale Street, although below the level of businesses and residences. Most of downtown Memphis is on a bluff, so landmarks like historic Sun Studio, where music legends Elvis Presley and Johnny Cash got their starts, were not seeing flooding. Tour guide Jake Fly said people north and south of the city are "really feeling it."

"We're all hoping this river is going to crest soon, man," said Fly. "Man, it's something to see."

The National Weather Service forecast that the river will crest Wednesday in Memphis at 48 feet, just under the 1937 record. No significant rain is forecast for the next few days in the area. The weather service expects record crests in Mississippi at Vicksburg on May 20 and Natchez on May 22.

No deaths or injuries have been reported in the Memphis flooding, but the spectacle has drawn sightseers -- an activity being discouraged by emergency officials.

"Most of the tourists weren't trying to visit the clubs on Beale Street, but they were trying to touch the water," said Joseph Braslow, 20, son of one of the owners of A. Schwab Dry Goods on Beale Street.

Further north in Missouri, the river was cresting Saturday afternoon at Caruthersville, said Ryan Husted, meteorologist for the National Weather Service in Memphis. New Madrid, Missouri and Tiptonville, Tenn. crested at 48.35 Saturday and levels are falling.

The U.S. Coast Guard closed a portion of the Ohio River Saturday. The Coast Guard closed the Mississippi at Caruthersville briefly Friday.

Shular said a major concern is flooding along the tributaries of the Mississippi. These smaller streams and rivers usually flow into the larger river, but are "hitting a brick wall" and backing up.

In Arkansas, a portion of Interstate 40, a major national road artery for trucking, remained closed on Saturday due to flood waters.

In the state of Mississippi, over 2,000 residents will have to evacuate as the river continues to rise, according to Jeff Rent, director for external affairs for the Mississippi Emergency Management Agency.

"It will be much higher" than 2,000, Rent said. "There just does not seem to be an end to these emergencies lately."

A snowy winter spawned near-record crests on the Upper Mississippi this year that reached southern Illinois at about the same time as heavy rain swelled the Ohio River.

The resulting flows have threatened to overwhelm the intricate flood levee system, prompting the U.S. government to open a Missouri floodway for the first time since 1937 to relieve pressure. U.S. officials are expected to activate three floodways this year for the first time in history.

The U.S. government blew a hole in the Birds Point levee last Monday, flooding Missouri farmland to save some Illinois and Kentucky towns.

The U.S. plans to open the Bonnet Carre Spillway 28 miles north of New Orleans on Monday to relieve pressure on the city by diverting some of the flow to Lake Pontchartrain. It also could open the Morganza Spillway farther north by Thursday.

This year's flooding is set to eclipse numerous crest records set mainly in 1927 and 1937. The Great Flood of 1927 swelled the Lower Mississippi to 80 miles wide in some parts, caused up to 1,000 deaths by some estimates and drove more than 600,000 people from their homes.

Since 1927, levees have been raised and constructed with different methods, dozens of reservoirs have been added across the basin and floodways have been added.

(Writing by Mary Wisniewski; additional reporting by Tim Ghianni in Nashville and Leigh Coleman in Mississippi; Editing by Greg McCune)

BIRMINGHAM, Ala (Reuters) – The call for help came the morning after a killer tornado pulverized a section of Birmingham 10 days ago. Gordon Smelley and his "chainsaw gang" of 11 from the First Baptist Church in Clanton, Alabama started their trailer and headed out.

"I don't have a lot of money to give, but I can give a few hours work to help people the best way I can," said Smelley, 72, a retired electrician for the Alabama Power Company.

Calls like the one to Smelley were repeated across the ravaged Deep South of the United States, dubbed the "Bible Belt" for its strong religious tradition. Churches led the cleanup and comfort after dozens of tornadoes left more than 300 people dead and some communities little more than piles of rubble.

These are not naive, disorganized do-gooders. They are professional volunteers with first class equipment and meticulous training.

Smelley's crew maintains a trailer filled with chainsaws, safety glasses, chaps, gloves, extra chains and chainsaw repair tools. It is parked at a church member's home for fast access. Similar trailers dot the parking lots of churches from nearly every religious denomination in Alabama.

Some trailers open out into "feeding units," such as one maintained by the Baptist denomination that is a 53-foot semi-truck and can issue 25,000 meals a day.

Other units include a shower and laundry truck, emergency child-care trucks, supply trucks, and tool trucks like the chainsaw trailers, according to Keith Hinson, spokesperson for Baptist Disaster Relief. Several warehouses store the trailers packed with supplies and equipment.

"Katrina was the catalyst for us to become more prepared for emergencies," Danette Clifton, spokeswoman for the North Alabama Conference of the United Methodist Church, said of the 2005 hurricane that devastated New Orleans and other parts of the South.

Religion is more deeply rooted in the American South than any other region of the country. The two states hardest hit by the recent tornadoes, Mississippi and Alabama, ranked No. 1 and 2 among the states in the importance of religion to residents, according to a 2009 survey by the Pew Research center.

Some 82 percent of people in Mississippi said religion was very important to their lives and 74 percent in Alabama.

While the South is known for white Evangelical Christians such as the Baptists, it also has a diverse range of churches from mainstream Protestants and black Protestant churches to a growing number of Catholics and even non-Christian religions.

Volunteers such as Smelley train extensively for their roles in emergencies. He spent several days in classes at the Alabama Baptist Board of Missions State Conference.

Training courses include victim sensitivity, safety, first aid, food preparation, chainsaw operation and "mud out" for flooded homes. He was certified and issued an official badge enabling him to enter disaster areas. More than 2.500 volunteers have completed the training, according to Hinson.

Many of these church-sponsored trailers dotted dozens of sites in the affected areas. In Phil Campbell, a community badly hit by a twister, chickens from a damaged poultry farm were roasted on the grill, feeding victims and the 800 volunteers who came last Saturday to help with the cleanup.

Dozens of churches in the affected areas morphed into emergency rooms, shelters, command centers, child-care facilities, and donation sites for receiving and giving.

On Sunday, religious leaders are planning what they call a "Super Sunday," when preachers will ask from the pulpit for a massive outpouring of volunteers across the state.

"People were mighty gracious and glad to see us," said Smelley, who worked 12 hour days last weekend in Pratt City near Birmingham.

At the tiny town of Phil Campbell, the Spanish Seventh Day Adventist Church showed up with 35 people -- every teenager and adult member of the congregation -- with chain saws, gloves and willing hearts.

"This is what Jesus taught us to do," said a volunteer for the Spanish church, Carlos Baltazar.

(Editing by Greg McCune)

ATLANTA (Reuters) – Al Qaeda and its allies will keep targeting the West despite the killing of Osama bin Laden and the United States must remain "ever vigilant," Homeland Security Secretary Janet Napolitano said on Saturday.

Napolitano said the U.S. government had nevertheless not formally raised alert levels in its National Terrorism Advisory System since U.S. commandos killed the al Qaeda leader at a compound in Pakistan nearly a week ago.

"What that means is that we have no specific, credible intelligence right now that would indicate that we do so. But we are constantly, with our intelligence partners feeding into us, evaluating that posture," she told an audience at the Atlanta Press Club.

While Napolitano hailed bin Laden's killing as "probably one of the most significant achievements yet" in the U.S. fight against terrorism, she warned against the United States and its Western allies lowering their guard.

"There really is no doubt that al Qaeda, or an al Qaeda affiliate, or those inspired by that ideology, will continue to focus their attacks on the West," she said. "What this means is that we have to remain ever vigilant."

Napolitano spoke as a senior U.S. intelligence official in Washington told journalists that the compound in Pakistan where bin Laden was killed was an "active command and control center" for the al Qaeda leader.

Addressing U.S. government efforts to curb illegal immigration on its southern border, Napolitano, a former Arizona governor, said federal authorities were making progress in improving border security.

"There has never been a larger, more sustained and better effort," she said.

Napolitano rejected criticism by some states that President Barack Obama's administration was not doing enough to halt the unlawful influx of migrants. States like Arizona and Georgia have toughened measures against illegal immigrants.

"I think these efforts at the state-by-state level ... they're predicated on a falsity. The falsity is that there has been nothing done, that the border somehow is out of control. That is incorrect," she said.

(Editing by Pascal Fletcher and Chris Wilson)