Tornadoes killed at least 17 people on Sunday and Monday. But some managed to stay safe in underground shelters like the one at right in Vilonia, Ark. Karen E. Segrave/AP hide caption

itoggle caption Karen E. Segrave/AP

A happy twist of events: Jacob Montgomery and Dexter are reunited. Courtesy of the Illinois National Guard hide caption

itoggle caption Courtesy of the Illinois National Guard

Barbara Garcia, right, sits with friends after a tornado destroyed much of their neighborhood in Moore, Okla. During an interview with CBS, Garcia found her dog buried in the wreckage of her house. Brett Deering/Getty Images hide caption

itoggle caption Brett Deering/Getty Images

Residents survey the destruction after a tornado hit Pratt City, Ala. just north of downtown Birmingham, Ala. on Wednesday, April 27, 2011. Butch Dill/AP hide caption

itoggle caption Butch Dill/AP