Slideshow: Boston Marathon bombing anniversary

People photograph a banner reading "Boston Strong" as it hangs at Rowes Wharf on the first anniversary of the Boston Marathon bombings, Tuesday, April 15, 2014, in Boston. (AP Photo/Bill Sikes)

A day of tributes and a moment of silence will mark the one-year anniversary of the Boston Marathon bombings. Three people were killed and more than 260 were wounded when two bombs went off near the finish line of the race.