It's the 16th annual Race to Wrigley 5K, benefiting Cubs Charities, and runners get to support the cause by running right into the ballpark.
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The Race to Wrigley 5K stepped off at 8 a.m., taking runners through Lakeview and then into the friendly confines, even onto the warning track, before a photo finish near the marquee.
Organizers said over 4,000 people were participating in-person and virtually this year.
"It's an incredible day to kick off the fall running season in-person," Cubs Charities Executive Director Alicia Gonzalez said.
The race was not held in-person last year due to the COVID pandemic.
It's the 16th annual event, which organizers said benefits Cubs Charities with a goal of supporting families through sport.
Over $250,000 were raised for Cubs Charities, with additional personal fundraising going to Advocate Children's Hospital, organizers said.