A still image from a video shows two tornadoes approaching Pilger, Neb., Monday. The National Weather Service said at least two people died in the large storm that hit northeast Nebraska.
After a tornado leveled Moore, Okla., last year, firefighter Shonn Neidel (left) developed an app that helps first responders locate storm shelters under the wreckage.
Courtesy of Shonn Neidel
A severe thunderstorm wall cloud is seen over the area of Canton, Miss., on Tuesday. At least 35 people in six states have been killed by tornadoes unleashed by a ferocious storm system this week.
Travel trailers and motor homes were piled on top of each other at Mayflower RV in Mayflower, Ark., on Sunday after tornadoes carved through the central and southern U.S.
This ominous-looking wall of clouds formed near Purcell, Okla., on Thursday. There were more tornadoes in Oklahoma and Arkansas as severe weather continued to pummel those states.
Students and teachers from Eastlake Elementary and Plaza Towers Elementary schools gathered Thursday to say goodbye for the summer. This was a chance to reconnect after the devastating tornado brought an abrupt end to the school year at Plaza Towers in Moore, Okla.
Katie Hayes Luke for NPR
Floodwaters from Superstorm Sandy destroyed the first floor of this house in Staten Island, New York. Most of the people who drowned during the storm died in their homes in low-lying areas of New York and New Jersey.
Paul J. Richards/AFP/Getty Images