Frank Siller, chairman and CEO of the Tunnel to Towers Foundation, has written a new book, "Let Us Do Good," recounting how the death of his younger brother Stephen, a New York City firefighter killed on 11 September 2001, reshaped his life and inspired his charitable mission. In an opinion piece marking the approaching 25th anniversary of the attacks, Siller describes the moment he learned his brother was gone, illustrating how personal tragedy from that day continues to drive remembrance and public service efforts across America.

Siller recalls repeatedly trying to reach Stephen by phone on the day of the attacks before receiving a call from a fellow firefighter, Richie Obermeyer, who was at Ground Zero and confirmed no one would be coming home. He describes the raw grief that followed among his family, including his wife Pat and daughter Elizabeth, and frames the experience as the origin point for his subsequent work leading the Tunnel to Towers Foundation. Siller is due to discuss the book on Fox News Channel's "The Five" on 1 September at 5pm ET.