Two men died and a third overdosed after sharing a batch of heroin, and police are investigating whether the heroin was tainted with the painkiller fentanyl. Fentanyl is "between 50 and 100 times more potent than morphine," and the police say that most of the fentanyl found in the overdoses was illegally made. Some are attracted to the tainted heroin because it is so dangerous - in Chicago, 117 people have died from the killer mix since April 2005! So far, 23 New Yorkers have died from the fentanyl-heroin mix since May, and one law enforcement official told the Daily News in August, "The danger is that it is so potent, so we're afraid some kid trying it out on a dare for the first time winds up dead."