FILE - In this Nov. 24, 1963, file photo, Detroit Lions' Nick Pietrosante, left, and Wayne Walker (55) stand during ceremonies honoring slain President John F. Kennedy before an NFL football game against the Minnesota Vikings at Metropolitian Stadium in Minneapolis. Americans grieved in front of their televisions on a brutally grim Sunday afternoon 50 years ago as a horse-drawn caisson took the body of President Kennedy to lie in state in the Capitol rotunda. As unimaginable as it might seem today, in seven cities men played football as the NFL went on despite the assassination two days earlier. (AP Photo/File)