Office workers observe a moment of silence in honor of the victims of the Boston Marathon bombing on Boylston Street near the race finish line, Monday, April 22, 2013, in Boston, Mass. At 2:50 p.m., exactly one week after the bombings, many bowed their heads and cried at the makeshift memorial on Boylston Street, three blocks from the site of the explosions, where bouquets of flowers, handwritten messages, and used running shoes were piled on the sidewalk. (AP Photo/Robert F. Bukaty)