The deadly tornado that ripped through the midwestern state of Oklahoma on Monday left entire neighborhoods flattened, homes, businesses and schools destroyed. As emergency workers sift through the wreckage Tuesday, survivors are sharing their experiences.
Among the countless buildings struck by the three-kilometer-wide tornado were two elementary schools - hit just as students were about to be released for the day.
Sherry Biddle, a teacher at Briarwood Elementary School, described how she helped her students protect themselves.
Deadliest U.S. Tornadoes Since 1900
March 1925: 695 killed in Missouri, Illinois and Indiana
April 1936: 216 killed in Tupelo, Missouri
April 1939: 203 killed in Gainesville, Georgia
April 1947: 181 killed in Woodward, Oklahoma
May 2011: 158 killed in Joplin, Missouri
April 1908: 143 killed in Louisiana and Mississippi
June 1953: 116 killed in Flint, Michigan
May 1953: 114 killed in Waco, Texas
"I had them take their backpacks and put them over their heads, just as another safety precaution, in the center of our room, in the center of our building," she said.
Briarwood third-grade student Caden talked about what he experienced as the tornado passed.
"I was on the ground, and I just, my ears just went WHOOO, and I couldn't hear anything except cracking and kids screaming," he said.
Incredibly, all the students at Briarwood Elementary School have been accounted for. Another school, Plaza Towers, was not so lucky.
Comparison of Tornado paths in Moore, Oklahoma - May 3, 1999 and May 20, 2013
As of early Tuesday, police said seven students had died there and at least 24 were missing. In the chaos following the storm, rescuers and parents searched frantically for surviving children.
One emotional parent was able to locate his child. "I'm just happy that I was able to find my son and that my family's okay," he said.
Oklahoma Governor Mary Fallin said "hearts are broken'' for parents looking for their children. She deployed the state National Guard and extra police to assist with rescue operations.