The fall happened as he was leaving the ballpark.
The Cubs issued this statement Wednesday:
"Following yesterday's game, a male fan was injured after a fall as he was exiting the ballpark. Paramedics responded immediately and transported him to a local hospital. We have since learned he passed away today though we have no further information. The thoughts and prayers of our entire organization are with his family during this difficult time."
An autopsy for Garrity is scheduled for Thursday.