The "Last Column" is a relic that symbolizes the work of the rescue, recovery and cleanup period after the Sept. 11, 2001, attacks. ABC News went inside the 9/11 Memorial & Museum to witness the space that's dedicated to making sure people never forget. ▻

The "Last Column" is a relic that symbolizes the work of the rescue, recovery and cleanup period after the Sept. 11, 2001, attacks. ABC News went inside the 9/11 Memorial & Museum to witness the space that's dedicated to making sure people never forget. ▻ ↧ 9/11 25th anniversary live updates: Families gather for ceremonies ... Friday marks 25 years since the Sept. 11, 2001, terror attacks, which claimed the lives of 2,977 people at the World Trade Center, the Pentagon and Shanksville.