A wheat field is inundated with floodwater near Vicksburg, Miss. The Mississippi River at Vicksburg is expected to crest at a record level Thursday. Scott Olson/Getty Images hide caption

itoggle caption Scott Olson/Getty Images

Mississippi floodwaters creep up the Old Train Depot and flood walls of downtown Vicksburg, Miss., on Friday. Rogelio V. Solis/AP hide caption

itoggle caption Rogelio V. Solis/AP

Haiti's 2010 earthquake destroyed more than 80 percent of schools in and around Port-au-Prince. Thony Belizaire/AFP/Getty Images hide caption

itoggle caption Thony Belizaire/AFP/Getty Images

Electoral workers count ballots by candlelight at a polling station at the end of a presidential runoff in Port-au-Prince, Haiti, on Sunday. The two choices were Mirlande Manigat, the former first lady, and Michel "Sweet Micky" Martelly, a Haitian music star. Results are expected at the end of March. Ramon Espinosa/AP hide caption

itoggle caption Ramon Espinosa/AP

A banner in Haiti's Cite Soleil neighborhood encourages residents to vote Sunday in the second round of elections. Allison Shelley/Getty Images hide caption

itoggle caption Allison Shelley/Getty Images

The San Onofre power plant is one of California's two nuclear power plants located near active earthquake faults. The other is Diablo Canyon power plant in San Luis Obispo County. Mark Ralston/AFP/Getty Images hide caption

itoggle caption Mark Ralston/AFP/Getty Images

Mourners pay respects to Ruben Salazar, Sept. 1970. Photo Courtesy of UCLA Library's Digital Collection, Changing Times: Los Angeles in Photographs, 1920-1990 UCLA Library hide caption

itoggle caption UCLA Library