For Paul Cotter, being a firefighter wasn’t a job, it was a calling. Nearly three decades of running toward danger, including a three-alarm fire where he broke through two doors and crawled into an inferno to save a man trapped on the third floor. Then came a phone call from his doctor. Cancer. His wife, Diane Cotter, says she screamed when she found out. And she says, as Paul began to slip further and further away, one question haunted her: how does this happen to someone so healthy? Diane knew the risks everyone associates with firefighting: smoke, toxins and diesel exhaust. But she had also seen the numbers: cancer is now the leading cause of line-of-duty death for firefighters. And she couldn’t shake the feeling there was more to the story. So, she went to the basement and pulled out Paul’s turnout gear, the uniform designed to protect him. What she noticed stopped her cold: the material was especially degraded in one specific area. Diane cut small samples from the gear and s...