Colorado lawmakers are considering a proposal to allow a legal drug injection site in Denver for heroin users.

Under the proposed bill, the site would allow illegal drug users to shoot up under medical supervision without fear of being prosecuted, KDVR reported.

The idea behind the bill, according to some lawmakers, is that a medically-trained supervisor can provide life-saving medical interventions if a drug user overdoses.

State lawmakers got the idea for the legal injection site after touring a similar site in Vancouver, British Columbia.

“One site we visited had over 4 million visits over the past years,” said state Rep. Leslie Heron (D-Denver). “And they have reported zero overdose deaths, zero.”

But the bill’s sponsors told the Denver Post that their legislative efforts could die in committee, as many opponents of the bill expressed concerns about whether the state should be endorsing illegal activity.

“Initially, the trepidation I have is over creating enclaves of illegal activity and calling it legal,” said Senate President Kevin Grantham (R-Cañon City), one of the opponents of the bill.

Other cities have proposed plans to create “legal injection sites” or “safe injection sites” for illegal drug users.

In January 2017, Seattle approved the first “safe injection site” in the U.S. for illegal drug users.