In pictures: US tornado leaves trail of devastation and death

SAN DIEGO, CA - MAY 20: St. Louis Cardinals players bow their heads during a moment of silence for the Oklahoma tornado victims before a baseball game against the San Diego Padres at Petco Park on May 20, 2013 in San Diego, California. Denis Poroy/Getty Images/AFP== FOR NEWSPAPERS, INTERNET, TELCOS & TELEVISION USE ONLY == *** Local Caption *** 161759-01-09.jpg

Flipped vehicles are piled up outside the heavily damaged Moore Medical Centre after the powerful tornado ripped through the area. Brett Deering/Getty Images/AFP

Two girls stand in rubble after the tornado struck Moore. Reuters/Gene Blevins

A woman is pulled out from under tornado debris at the Plaza Towers School in Moore, Oklahoma. AP Photo / Sue Ogrocki

This aerial photo shows damage to Moore Medical Center after it was hit by the massive tornado. AP Photo/Steve Gooch

A child calls to his father after being pulled from the rubble of the Tower Plaza Elementary School following the tornado. AP Photo/Sue Ogrocki

This aerial photo shows the remains of homes hit by a massive tornado in Moore, Oklahoma. AP Photo / Steve Gooch

Kay James holds her cat as she sits in her driveway after her home was destroyed by the tornado that hit the area. AP Photo/The Oklahoman, Chris Landsberge

The tornado roared through the Oklahoma City suburbs, flattening entire neighborhoods, setting buildings on fire and landing a direct blow on an elementary school. AP Photo/Steve Gooch

Clark Gardner, at left, and another man place an American flag on debris in a neighborhood off of Telephone Road in Moore, Oklahoma, after the tornado moved through the area. AP Photo/ The Oklahoman, Bryan Terry