Red Cross volunteer and Boston hero Carlos Arredondo (right) participated in the Blessing of the Athletes service at the Old South Church on Sunday. Jessica Rinaldi/The Boston Globe/Getty Images
At 2:49 p.m. on April 15, 2013, two explosions on Boylston Street forever changed the Boston Marathon -- and the people involved. Friends, family and fans paid tribute over the weekend to remember 29-year-old Krystle Campbell, 8-year-old Martin Richard, 23-year-old Lingzi Lu, 27-year-old MIT patrol officer Sean Collier, and the survivors.
