Boston bombing survivor Rebekah Gregory writes note to younger self

It has been 10 years since a bomb exploded just feet from Rebekah Gregory and her son Noah as they attended the Boston Marathon as spectators. Gregory's body shielded the 5-year-old, but she was seriously injured, eventually losing her left leg. For our series Note to Self, Gregory shares a letter with her younger self about what happened that day, her determination and mission to help others.