Players and coaches around the NFL reacted with shock and sadness Tuesday after a gunman killed four people at the New York office building housing the league's headquarters

The man who opened fire in a Midtown Manhattan office building, killing four people and wounding a fifth, appeared to be targeting the NFL headquarters and had a note claiming he suffered from CTE, police sources told ABC News.

Shane Tamura, the shooter behind the deadly rampage in Midtown Manhattan,​ was apparently targeting NFL offices, NYC Mayor Eric Adams says.