At the very outset of Hannah Dreier’s searing investigation, a 14-year-old named Marcos nearly loses his arm while cleaning a chicken slaughterhouse. Given that word, “nearly,” it’s understandable that you’d hope for some kind of happy resolution. But just because Marcos keeps all his body parts doesn’t mean that something fundamental hasn’t been ripped away from him—or any of the other thousands of migrant children who come to the U.S. and work dangerous overnight jobs in hopes of helping their families. A difficult read, but a necessary one.

While teenagers work legally all over America, Marcos’s job was strictly off limits. Federal law prohibits 14- and 15-year-olds from working at night or for more than three hours on school days. Older teenagers are allowed to put in longer hours, but all minors are barred from the most dangerous occupations, including digging trenches, repairing roofs and cleaning slaughterhouses.

But as more children come to the United States to help their families, more are ending up in these plants. Throughout the company towns that stud the “broiler belt,” which stretches from Delaware to East Texas, many have suffered brutal consequences. A Guatemalan eighth grader was killed on the cleaning shift at a Mar-Jac plant in Mississippi in July; a federal investigation had found migrant children working illegally at the company a few years earlier. A 14-year-old was hospitalized in Alabama after being overworked at a chicken operation there. A 17-year-old in Ohio had his leg torn off at the knee while cleaning a Case Farms plant. Another child lost a hand in a meat grinder at a Michigan operation.