The Louisville Metro Police Department is investigating a recent drug bust where officers allegedly uncovered enough fentanyl to kill 4 million people. According to NBC 15, U.S. Drug Enforcement Administration and Louisville officials concluded a long-term operation when they seized at least 8.5 kilograms of fentanyl and 20,000 to 30,000 suspected fentanyl pills from a Louisville-area storage unit last week. According to the DEA, merely one kilogram of the drug has the potential to kill 500,000 people.