Does Basketball/Football Kill People?

It is quite possible that basketball or other popular sports such as football and baseball can kill people. Not necessarily the people on the court, but the people off of it. Namely the fans. There were three shootings near the Warriors celebration parade. Now, it hasn't been officially connected to the parade, but most believe that there is a connection. This isn't, however, the only incident where violence has been used for sports. There were multiple deaths when the Jordan 11s were released and numerous other accounts all for a game. Where does this stop? Should the NBA and NFL be sued? Should the teams be sued? Are is this just a natural part of the game and continue on as it is? Voice your opinions in the comments below.