Prepare for 'mass-overdose' events from fentanyl, DEA warns police nationwide

The leading U.S. drug enforcement agency issued an unprecedented warning to law enforcement nationwide to brace for a spike in “fentanyl-related mass-overdose” deaths as Mexican cartels push the drug into the United States.

The Drug Enforcement Administration sent a letter to federal, state, and local law enforcement departments nationwide Wednesday, alerting officials they should prepare not only for deaths caused by fentanyl to rise but also for mass-casualty events in which a group of people dies as a result of knowingly or unknowingly overdosing.

“Fentanyl is killing Americans at an unprecedented rate,” said DEA Administrator Anne Milgram...