About a week prior to Monday’s running of the Boston Marathon, and a year after the bombing at the 2013 marathon, photographer Gregory Heisler addressed a crowd of thousands gathered at the finish line. The group included runners, first responders and Boston Mayor Marty Walsh, all ready to pose for Sports Illustrated's 'Boston Strong' cover photo. Directing the crowd through a megaphone and standing on a raised platform, Heisler captured a portrait of 3,000 proud, resilient Bostonians.  

Sports Illustrated is offering a look behind the making of this photograph, including the short video below. In it, Heisler speaks briefly about the large crowd who answered the casting call for the shoot, saying 'It's incredible to see that resiliency, and to see people coming together like this. It's not surprising'. You can also pan and zoom around the cover photo thanks to Gigapan.