A tense moment at Wrigley Field turns physical when an older Cubs fan slaps a younger fan who refused to stand up during the national anthem. The older fan is

A tense moment at Wrigley Field turns physical when an older Cubs fan slaps a younger fan who refused to stand up during the national anthem. The older fan is heard telling him to "stand up" before striking him in the back of the head. The younger fan then stands as nearby spectators react. Author…