MINNEAPOLIS — The Hennepin County Sheriff’s Office says 54 people died as a result of heroin overdoses in the county last year.

The number is a record high for the county — and a sharp increase from three years ago, when just eight people died from heroin overdoses in 2010.

Sheriff Rich Stanek says investigators have found heroin users in all parts of the county.

Authorities say the growing popularity of heroin can be directly linked to prescription painkiller abuse. Both are opiates, and once painkillers run out, addicted people may turn to heroin on the street.

Authorities say heroin in the Twin Cities is inexpensive and has one of the highest purity levels in the nation — so new users who buy the drug cheaply don’t know how powerful it is.