US President Barack Obama pauses while speaking at Missouri Southern University May 29, 2011 during a memorial for victims of the Joplin, Missouri, tornado. Victims of the tornado continue to recover as 2011 becomes the deadliest year for tornadoes since 1953. The death toll stood at 142 one week after the tornado cut a path of death and destruction through the heart of this town of 50,000. AFP PHOTO/Brendan SMIALOWSKI (Photo credit should read BRENDAN SMIALOWSKI/AFP/Getty Images)