Lapatilla
US President Barack Obama and First Lady Michelle Obama arrive to board Air Force One at Andrews Air Force Base in Maryland on April 18, 2013. Obama heads to Boston to mourn victims of the deadly marathon attacks, as investigators study images of a suspect who may have planted the bombs. No arrests have been made in connection with Monday’s twin bombings near the finish line of the race, which sent metal fragments and nails into a crowd of thousands of runners and spectators, killing three people and wounding 180. AFP PHOTO/Jewel Samad