PLAINFIELD TOWNSHIP, Mich. (WOOD) — This Sunday marks the 21st anniversary of the 9/11 terror attacks.

The National Fallen Firefighters Foundation’s annual 9/11 stair climb is happening Saturday at LMCU Ballpark to pay tribute to the firefighters who gave their lives on that day.

Participants are invited to climb 110 flights of stairs, which symbolizes the route taken by the firefighters killed at the World Trade Center on 9/11. The stair climbing event helps support the foundation as well as programs for all families of firefighters who have died in the line of duty.

“The individuals that gave their lives 21 years ago did so for complete strangers,” said Edwin Marino, the co-coordinator for the event. “That unselfishness and that desire to help others is something that we desperately need in our culture today, for communities to come together, for individuals to reach out to each other, and unite and help each other.”

The stair climb will take place from 9 a.m. until noon. Adults who participate will be asked to make a $30 donation. The event is free for kids under 18.

Donuts and a pancake breakfast will be available for all participants.