A neighborhood destroyed by a powerful tornado on Sunday is seen in Joplin, Mo. Tuesday, May 24, 2011. A tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 116 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel, ASSOCIATED PRESS

An apartment complex destroyed by a powerful tornado is seen in an aerial view over Joplin, Mo. Tuesday, May 24, 2011. A tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 116 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel, ASSOCIATED PRESS

This aerial photograph shows a neighborhood destroyed by a powerful tornado in Joplin, Mo. Tuesday, May 24, 2011. A tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 116 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel, ASSOCIATED PRESS

A neighborhood destroyed by a powerful tornado is seen in an aerial photo taken over Joplin, Mo., Tuesday, May 24, 2011. A tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 116 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel, ASSOCIATED PRESS

This aerial photograph shows a neighborhood destroyed by a powerful tornado in Joplin, Mo. Tuesday, May 24, 2011. A tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 116 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel, ASSOCIATED PRESS

The path of a powerful tornado is seen in Joplin, Mo., Tuesday, May 24, 2011. A tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 116 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel, ASSOCIATED PRESS

The path of a powerful tornado is seen in an aerial photo over Joplin, Mo., Tuesday, May 24, 2011. A tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 116 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel, ASSOCIATED PRESS

The path of a powerful tornado is seen in Joplin, Mo. Tuesday, May 24, 2011. A tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 116 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel, ASSOCIATED PRESS

A neighborhood destroyed by a powerful tornado is seen in an aerial photo taken over Joplin, Mo., Tuesday, May 24, 2011. A tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 116 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel, ASSOCIATED PRESS

A destroyed apartment complex is seen in an aerial view over Joplin, Mo. Tuesday, May 24, 2011. A tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 116 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel, ASSOCIATED PRESS

A neighborhood destroyed by a powerful tornado on Sunday is seen in Joplin, Mo. Tuesday, May 24, 2011. A tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 116 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel, ASSOCIATED PRESS

The path of a powerful tornado is seen in Joplin, Mo. Tuesday, May 24, 2011. A tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 116 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel, ASSOCIATED PRESS

The path of a powerful tornado is seen in Joplin, Mo. Tuesday, May 24, 2011. A tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 116 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel, ASSOCIATED PRESS

A firefighter searches a home Monday, May 23, 2011, that was destroyed by a tornado in Joplin, Mo. A large tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 89 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel, AP

FILE - This May 29, 2011 file photo shows President Barack Obama, second from left, with residents viewing damage from the tornado that devastated Joplin, Mo. A month packed with tornadoes and flooding has caused billions of dollars of damage in Missouri. And the economic aftershocks may be felt for years. (AP Photo/J. Scott Applewhite) Photo: J. Scott Applewhite

FILE This undated family photo shows the crushed Hummer Will Norton was driving when a tornado hit Joplin, Mo. on Sunday, May 22, 2011. Norton was killed during the tornado which pulled him out through his SUV’s sunroof as he drove home from his high school graduation. (AP Photo/Family Photo, File)

President Barack Obama, second from left, seen with officials and residents, views damage from the tornado that devastated Joplin, Mo., Sunday, May 29, 2011. He is joined by Missouri Gov. Jay Nixon. (AP Photo/J. Scott Applewhite) Photo: J. Scott Applewhite

President Barack Obama views damage from the tornado that devastated Joplin, Mo., Sunday, May 29, 2011. Obama is joined by Missouri Gov. Jay Nixon, second from right, and FEMA Director William Fugate, left. (AP Photo/J. Scott Applewhite) Photo: J. Scott Applewhite

Rev. Janice Kibler talks to the congregation Sunday, May 29, 2011 in the parking lot at Peace Lutheran Church which was destroyed in Joplin, Mo. one week ago. An EF-5 tornado tore through much of the city damaging a hospital and hundreds of homes and businesses and killing at least 139 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel

President Barack Obama reaches out to residents while viewing damage from the tornado that devastated Joplin, Mo., Sunday, May 29, 2011. He is joined by Missouri Gov. Jay Nixon. (AP Photo/J. Scott Applewhite) Photo: J. Scott Applewhite

President Barack Obama, third from left, talks with residents while viewing damage from the tornado that devastated Joplin, Mo., Sunday, May 29, 2011. (AP Photo/J. Scott Applewhite) Photo: J. Scott Applewhite

President Barack Obama talks to residents and views damage from the tornado that devastated Joplin, Mo., Sunday, May 29, 2011. (AP Photo/J. Scott Applewhite) Photo: J. Scott Applewhite

President Barack Obama views damage from the tornado that devastated Joplin, Mo., Sunday, May 29, 2011. (AP Photo/J. Scott Applewhite) Photo: J. Scott Applewhite

President Barack Obama speaks at a memorial service at Missouri Southern State University for the victims of the tornado that devastated Joplin, Mo., Sunday, May 29, 2011. (AP Photo/J. Scott Applewhite) Photo: J. Scott Applewhite

President Barack Obama reacts to comments on the damage from the tornado that devastated Joplin, Mo., Sunday, May 29, 2011. (AP Photo/J. Scott Applewhite) Photo: J. Scott Applewhite

Residents wave as President Barack Obama views damage from the tornado that devastated Joplin, Mo., Sunday, May 29, 2011. (AP Photo/J. Scott Applewhite) Photo: J. Scott Applewhite

A flag files at half staff over devastated Joplin High School in Joplin, Mo. Thursday, May 26, 2011. An EF-5 tornado tore through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 125 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel

A search and rescue team member looks for victims at a devastated apartment complex in Joplin, Mo. Thursday, May 26, 2011. An EF-5 tornado tore through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 125 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel

Names spray painted on a garage door indicate the status of residents of a home in a devastated Joplin, Mo. neighborhood Thursday, May 26, 2011. An EF-5 tornado tore through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 125 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel

Residents look at an acoustic guitar while searching through the wreckage of their third-floor apartment on the east side of Joplin, Mo., Tuesday, May 24, 2011. At least 116 people were killed and hundreds more injured when a tornado cut a destructive path through Joplin on Sunday evening. (AP Photo/Mark Schiefelbein) Photo: Mark Schiefelbein

Members of Missouri Task Force One search-and-rescue team work at a tornado-damaged Home Depot store Tuesday, May 24, 2011, in Joplin , Mo. A large tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses. (AP Photo/Jeff Roberson) Photo: Jeff Roberson

Amy Gilbert stands in what is left of her kitchen Tuesday, May 24, 2011, in Joplin , Mo. Gilbert and her husband, Eric, were standing in the kitchen as the roof began to tear away from the house during a tornado Sunday night. The couple was able to seek shelter in a bathroom off the kitchen along with their eight-year-old daughter their dogs and a friend. All survived without injury. (AP Photo/Jeff Roberson) Photo: Jeff Roberson

A woman makes her way into the damaged main entrance of Joplin High School in Joplin, Mo., Tuesday, May 24, 2011. At least 116 people were killed and hundreds more injured when a tornado cut a destructive path through Joplin on Sunday evening. Classes at all Joplin schools have been canceled for the rest of the schoolyear after four schools were damaged or destroyed. (AP Photo/Mark Schiefelbein) Photo: Mark Schiefelbein

Wheelchairs salvaged from the wreckage of the Greenbriar nursing home sit in the facility's parking lot in Joplin, Mo., Tuesday, May 24, 2011. At least 116 people were killed and hundreds more injured when a tornado cut a destructive path through Joplin on Sunday evening. (AP Photo/Mark Schiefelbein) Photo: Mark Schiefelbein

Steve Stafford and Kathy Butler help salvage belongings from the apartment of a friend in Joplin, Mo., Tuesday, May 24, 2011. At least 116 people were killed and hundreds more injured when a tornado cut a destructive path through Joplin on Sunday evening. The man who lived in the apartment survived with cuts and bruises by huddling in a closet at the rear, despite having a neighbor's car thrown through the building. (AP Photo/Mark Schiefelbein) Photo: Mark Schiefelbein

Meghan Miller stands in the middle of a destroyed neighborhood as she checks on her sister-in-law's home Monday, May 23, 2011, in Joplin , Mo. A large tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses. (AP Photo/Jeff Roberson) Photo: Jeff Roberson

Ashley Stephens holds a ferret she rescued from the home of a missing woman while helping a friend collect belongings Monday, May 23, 2011, in Joplin, Mo. A large tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 89 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel

Candice Kell, 17, looks over her psychology textbook inside her grandmother's home in Joplin, Mo., Monday, May 23, 2011 after it was damaged by a tornado that destroyed nearly 30 percent of the town on Sunday afternoon. Kell and her grandmother, Jean Logan, rode out the storm in the laundry room. The twister cut a six-mile path through the city. (AP Photo/Tulsa World, Adam Wisneski) Photo: Adam Wisneski

Emergency workers wait for a medical team after finding a body in a tornado ravaged car in Joplin, Mo., Monday, May 22, 2011. A large tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses. (AP Photo/Charlie Riedel) Photo: Charlie Riedel

Josh Ramsey looks through the rubble of what is left of his mother-in-laws home following a tornado Monday, May 23, 2011, in Joplin , Mo. A massive tornado that tore a six-mile path across southwestern Missouri killed at least 89 people as it smashed the city of Joplin, ripping into a hospital, crushing cars like soda cans and leaving behind only splintered tree trunks where entire neighborhoods once stood. (AP Photo/Jeff Roberson) Photo: Jeff Roberson

A shelf cloud containing a thunderstorm approaches a tornado-ravaged neighborhood in Joplin, Mo., Monday, May 23, 2011. A large tornado moved through much of the city Sunday, damaging a hospital, hundreds of homes and businesses and killing at least 89 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel

Rescue workers in lime-green jackets search for bodies and survivors inside St. John's hospital in Joplin, Mo. Monday, May 23, 2011. The hospital was damaged by a tornado that destroyed nearly 30 percent of the city on Sunday afternoon. (AP Photo/Tulsa World, Adam Wisneski) Photo: Wisneski Tulsa World

Jean Logan reacts as she sees the damage to her home in Joplin, Mo., Monday, May 23, 2011 after it was damaged by a tornado that destroyed nearly 30 percent of the town on Sunday afternoon. Logan and her granddaughter rode out the storm in the laundry room. The twister cut a six-mile path through the city. (AP Photo/Tulsa World, Adam Wisneski) Photo: Adam Wisneski

Mary Womack, in white top at the right, reacts to the news that the renter that lived in her house had been found and taken to the hospital on Monday, May 23, 2011. There were at least 89 deaths and numerous casualties from the tornado that struck Joplin, Mo. on Sunday. (AP Photo/Mike Gullett) Photo: Mike Gullett

A man salvages a guitar from a severely damaged home in Joplin, Mo., Monday, May 23, 2011. A large tornado moved through much of the city Sunday, damaging a hospital and hundreds of homes and businesses and killing at least 89 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel

The damaged St. John's Regional Medical Center is seen in the distance through tornado debris in Joplin, Mo., Monday, May 23, 2011. A large tornado moved through much of the city Sunday, damaging the hospital and hundreds of homes and businesses and killing at least 89 people. (AP Photo/Charlie Riedel) Photo: Charlie Riedel