YAZOO CITY, Miss. -- Some Mississippi residents cracked jokes Monday to keep from crying while they looked for salvageable items among the rubble left by severe storms that killed 12 people over the weekend.

State officials were tallying the cost of the damage so they could ask for an emergency declaration from President Barack Obama, along with federal funds to help clean up the mess. The latest figures Monday were grim: In Mississippi alone, nearly 700 homes were damaged, 49 people injured and 10 killed. Two others died in storms in Alabama.

Nancy Luke stepped carefully through fallen cinder blocks, cracked mirrors and a broken disco ball in what used to be the Yazoo City bar she managed, Wendy's On the Hill. The bar was in the center of the mile-wide swath of destruction.

Luke said she and the owner, Wendy Douglas, have been joking with each other to fend off tears. "She's a neat freak. This is usually the cleanest bar in town, I tell you," Luke said.

Most of the bar was obliterated, but the office and the restrooms still stood. Luke said she found three rolls of toilet paper still stacked in a pyramid on a tray in the women's room.

The tornado flung a blue metal trash container from outside the bar three miles away while dumping most of its contents next to the slab of the building: dozens of beer bottles, most of which were unbroken.

Miss. Gov. Haley Barbour was spending part of the day in neighborhoods of his native Yazoo City talking privately with residents.

"When you know everybody, it's harder," said Barbour, whose home was undamaged in Saturday's tornado.

President Obama called Barbour on Monday to express concern about the weekend storms. Obama "wanted to make sure they had everything they needed to respond to this tragedy," according to a White House statement. Federal Emergency Management Agency teams were working with state officials to assess the damage.

The storm system began in Louisiana before cutting a path some 150 miles long through Mississippi and continuing to Alabama. Storm surveyors were working Monday to determine whether the damage was caused by a single tornado or multiple twisters.