DENVER -- For the first time, officers with the Denver Police Department have confiscated bricks of fentanyl.
The drug has plagued many U.S. cities, but up until now has always been found in smaller quantities in Denver.
Most of the drug being sold on Denver streets is manufactured by drug cartels in Mexico.
Fentanyl is very potent. More than 2 milligrams of the drug can kill someone.
"There’s no way to measure that for street users. A street user takes a pill," said Todd Zimmerman with the Drug Enforcement Agency.
"Or anybody who takes the pill, there’s no way to measure how much is in there and it can cause respiratory failure and they can stop breathing immediately."
The Denver Department of Public Health and Environment is especially concerned about fentanyl because it's not only dangerous, but it's cheap and easy for addicts to get.
Pills typically sell for between $8 and $14 in Denver.