On the morning of Sept. 11, 2001, eight-year-old Amy Gaines’ father, Scott, dropped her off at the school bus stop. It was supposed to be the first day of his last vacation before retiring after 20 years as a New York City police officer. But after two planes struck the World Trade Center, Scott headed straight to Ground Zero, where he worked long, hard days for the next two months. Years later, he was diagnosed with cancer — joining thousands of 9/11 first responders suffering from illnesses they believed were linked to toxic exposure at the site.

In this episode of The FRONTLINE Dispatch, then-series coordinating producer Amy Gaines McQuade embarked on a deeply personal quest to understand the long arm of 9/11 through her father’s battle and the broader struggle of sickened first responders. Amy’s beautifully told story, titled “The Weight of Dust,” was originally published in 2018. We are re-releasing it to mark the 25th anniversary of the attacks.

The FRONTLINE Dispatch is available to stream on our website, Apple Podcasts, Spotify or wherever you get your podcasts.