Justin Tirelli is currently an Arlington County Fire Department captain, but 17 years ago he was a rookie firefighter in the ACFD ranks. On the morning of Sept. 11, 2001, Tirelli was responding to a fire call in Rosslyn when American Airlines Flight 77 struck the west side of the Pentagon. As his engine company was diverted to join the massive and heroic emergency response to the terror attack, Tirelli and his fellow firefighters focused on the task at hand -- not realizing that it would change them and the community they served forever. In this special episode of the 26 Square Miles podcast, we talked with Tirelli about what it was like to be a first responder at the Pentagon on that fateful day.