Four years ago today, Hurricane Katrina ripped through New Orleans, causing unprecedented devastation. In his weekly radio and Internet address, President Barack Obama marked the anniversary, vowing that the federal government will continue to assist with the city's recovery and that it has learned from the disaster. “As we remember all that was lost, we must take stock of the work being done on recovery, while preparing for future disasters,” Obama said. "None of us can forget how we felt when those winds battered the shore, the floodwaters began to rise, and Americans were stranded on rooftops and in stadiums." Earlier this week, the president announced the creation of a federal task force to help restore the Louisiana and Mississippi coastlines.