Col. Tim Duffy, call sign "Duff," was a fighter pilot on alert the morning of 9/11. Duffy, and Lt. Col. Dan Nash (call sign "Nasty"), were charged with flying from Otis Air National Guard Base in Massachusetts to New York City. Their mission was to protect innocent Americans from attack, and that mission could have included shooting down a commercial airliner.
Duff and Nasty talked to WBUR radio program "Here and Now" about the morning of 9/11 and what they saw and heard from their unique vantage point. You can click here to listen.