Cheap and very pure heroin is creating a growing addiction crisis across America. Heroin -- much of it from Colombia -- is replacing crack cocaine as the drug of choice, particularly among the young. In Massachusetts, for example, more than 4 percent of high school boys report having used heroin. In the '70s, a bag of heroin -- enough to get a user high once -- cost $30 and was about 28-percent pure. Today, it's 80 percent to 90 percent pure, which makes it powerfully addictive, and it sells for $4 a bag -- cheaper than a six-pack of beer. This is the first story in an unfolding five-part series on heroin. Running time is 7 minutes 32 seconds. (Requires RealPlayer) Heroin in America | NPR | 
