A hospital in New Haven, Connecticut treated 12 people who overdosed last June when they used fentanyl that had been sold as cocaine, according to the Centers for Disease Control and Prevention (CDC). Three of the people died. Fentanyl is an opioid that can be 50 times as strong as heroin, ABC News reports. Many fentanyl overdoses occur when the drug is sold as heroin, oxycodone or other opioids. A rapid response from public health officials and police may have saved lives, the CDC noted. Paramedics were equipped with additional naloxone, the opioid overdose antidote. Officials traced back the source of the drugs, issued a public service announcement and gave out naloxone to families and friends of people known to use opioids.