“His lips were ash white. His pupils were popping out,” Lilia Astudillo remembers about her 14-year-old son the night before he died of a fentanyl overdose in January. Two other students who also died are among nearly a dozen in one school district north of Dallas who have overdosed on fentanyl from September to March.

The overdoses have left a trail of shock, anger and grief in the community. It’s hardly the only place in the U.S. afflicted by the rise of fentanyl use among teens.