The title is actually (almost)accurate this time. 22 pounds translates to a bit more than 9,780,000 milligrams. The LD50, or lethal dose %50, meaning the dose that will kill %50 of people for fentanyl is 2mg. 9.78m/2 = 4.89. So it was enough to kill, roughly, 4.89 million people, presuming they have no opioid tolerance.