* Death toll from deadly U.S. twisters now at 310
* Obama due to view storm damage in Alabama city
* Cost of disaster could complicate state finances
By Verna Gates
TUSCALOOSA, Ala., April 29 (Reuters) - Rescuers in the tornado-ravaged U.S. South searched through debris for survivors and bodies on Friday ahead of a visit by President Barack Obama to the state worst hit by the disaster that killed 310 people.
Obama will view the destruction in Alabama, the hardest hit of seven states that were blasted this week by twisters and violent storms that flattened whole neighborhoods in the worst U.S. natural catastrophe since Hurricane Katrina in 2005.
In Alabama alone, 210 people lost their lives. Obama and his family were due to visit the university town of Tuscaloosa, which was savaged by a monster tornado on Wednesday.
The president is eager to show that federal relief is on its way and that he is not taking the disaster lightly. His predecessor President George W. Bush was fiercely criticized for what was viewed as a slow response to Hurricane Katrina.
Recovery could cost billions of dollars and even with federal disaster aid it could complicate efforts by affected states to bounce back from recession. It will place an added burden on municipalities grappling with fragile finances.
Tornadoes are a regular feature of life in the U.S. South and Midwest, but they are rarely so devastating. Deaths also were reported in Mississippi, Tennessee, Arkansas, Georgia, Virginia and Louisiana.
Full coverage of this week’s tornadoes [ID:nN28284934]
Tornado video link.reuters.com/jeg39r
Factbox on deadliest U.S. tornado days [ID:nN28269147]
At first light on Friday, state authorities deployed teams in Tuscaloosa, home to the University of Alabama, to help survivors still picking up the pieces after the swirling tornadoes on Wednesday devastated homes and businesses.
The twisters, including one a mile (1.6 km)-wide that cut a path of destruction, reduced houses to rubble, flipped cars and knocked out power and other utilities.
“We are bringing in the cadaver dogs today,” said Heather McCollum, assistant to the mayor of Tuscaloosa, who put the death toll in the city at 42 but said it could rise. She said 900 people were injured.
Hundreds of people were homeless because of the tornadoes and they stayed in shelters. A curfew would be renewed on Friday night to prevent looting, although there had been almost none, she said.
The city has been inundated with offers of help from around the country, McCollum told Reuters.
The worst hit areas of the city were largely deserted on Friday in part because of a curfew that ended at 6 a.m. local time (1100 GMT).
Wrecked McFarland Boulevard, normally one of the busiest streets, was largely blocked off and state troopers and city police patrolled its shattered shops and houses.
The storms left up to 1 million homes in Alabama without power. Because of the damage to infrastructure and gas stations, Alabama and the neighboring state of Tennessee advised people traveling to affected areas to fill up their tanks with gas.
Water and garbage collection services were also disrupted in some areas.
The storm threw into turmoil the University of Alabama. Two students died off campus and administrators canceled final exams and postponed graduation until August.
Many students slept in dorm rooms without power overnight and large numbers were heading home on Friday.
“Everyone is getting out,” said Katie Bayless, 19, whose parents had driven through the night from Houston, Texas, to collect her.
“I want every American who has been affected by this disaster to know that the federal government will do everything we can to help you recover, and we will stand with you as you rebuild,” Obama said on Thursday at the White House. (Additional reporting by Peggy Gargis in Birmingham and Colleen Jenkins in St. Petersburg, writing by Matthew Bigg, Editing by Pascal Fletcher and Will Dunham)