Americans are observing the 24th anniversary of the Sept. 11, 2001, attacks with ceremonies, volunteer work, and tributes honoring the nearly 3,000 victims.

Family members of those killed joined politicians and dignitaries at commemorations in New York, the Pentagon, and Shanksville, Pennsylvania.

Many attendees, like Denise Matuza, Jennifer Nilsen, and Michelle Pizzo, wore shirts with the names and photos of their husbands who died in the attacks, reflecting on the lasting pain of the tragedy.

For some, like Ronald Bucca, who lost his father in the attacks, the memorial is also a chance to educate younger generations about resilience, loss, and rebuilding after tragedy.

Pizzo emphasized the importance of remembrance, hoping people, especially young people, take even a moment to reflect on the events of that day, the Associated Press has reported.

This year’s tributes come amid heightened political tensions, just one day after the fatal shooting of conservative activist Charlie Kirk at a college in Utah.