America's endless battle against lethal drug fentanyl

Born from the overprescription of opioid painkillers, the opioid crisis has cost America more than 400,000 lives from 1999 to 2018, according to the US Centers for Disease Control and Prevention. One of the main dangers is fentanyl - a lethal synthetic opioid, 100 times more powerful than morphine. The US is fighting an endless battle to stop it from flowing in.