In his first public remarks since plans to open a supervised injection site in South Philadelphia were scrapped, Mayor Jim Kenney warned that people could die as a result.

“If people want to shut that down, then we’re going to have more people dying, more people using drugs and more suffering for families,” Kenney said.

Kenney’s warning came one day after a spokesman for Constitution Health Plaza announced late Thursday that the plaza was canceling plans to allow the nonprofit Safehouse to operate a supervised injection site on its premises.

The scrapping of the opening followed intense pressure and outrage by neighbors, city council members and federal authorities, who argued the decision to open the site was sprung on them by surprise.

Kenney acknowledged Safehouse officials could have had better communication with the public about the plan and said the nonprofit, not the city, chose the plaza to house the injection site, with the city only committing to security and social services assistance.

The nation's first supervised injection site for drug users will not be in South Philadelphia after all, NBC10 reporter Drew Smith found. What happened in a day that changed history?

However, he warned of the consequences that could come as the city grapples with an opioid crisis and people continue to use unsupervised.

“If city council and other elected officials want to shut down this opportunity to save lives, then they’re going to have to live with that – or die with that,” he said.

The battle to open a supervised injection site looked to be won earlier this week, when United States District Court Judge Gerald A. McHugh entered a final Tuesday on his ruling last year that Safehouse's proposal to open an injection site in Philadelphia does not violate federal law.

However, the decision caused furor among South Philadelphia residents, who said their neighborhoods would become unsafe and argued that children at the plaza – which holds both a school and day care center – would be exposed.

U.S. Attorney William McSwain, who earlier lost his bid to stop Safehouse from opening, announced he would appeal the ruling to the Third Circuit Court of Appeals. He filed a motion Thursday afternoon asking that the injection site not open until the conclusion of the appeals process.

McSwain filed a motion last year to stop Safehouse from opening a site, arguing that safe injections sites violate federal drug laws and would only further plunge Philadelphia into an opioid crisis.

Of particular focus in the argument was statute 856, also known as the "crack house" statute, which makes it illegal to "knowingly open, lease, rent, use, or maintain any place … for the purpose of unlawfully manufacturing, storing, distributing, or using a controlled substance."

McSwain seized upon public backlash as he labeled an earlier press conference announcing the opening of the injection site a “dumpster fire” and said the dispute could “deteriorate into a literal street fight.”

Philadelphia is the first place in the country to open a supervised injection site. NBC10’s Mitch Blacher tells us all we need to know about the facility in South Philly that will allow drug users to inject opioids.

The South Philadelphia site, chosen over a location in Kensington – the epicenter of the city's opioid epidemic – because of the nonprofit's current budget, was expected to be the first of several across Philadelphia, officials said.

It remains unclear if Safehouse will continue to pursue a safe injection site in Philadelphia. The group did not immediately respond to a request for comment about the canceled plans to open at Constitution Health Plaza.

Safehouse argues that allowing illegal drug use on its property will help prevent overdoses. Kenney, Philadelphia District Attorney Larry Krasner and former Pennsylvania Gov. Ed Rendell, who sits on Safehouse's board, all support an injection site in the city.

The issue has divided public officials in Philadelphia and around the nation, although similar sites are in use in Canada and Europe. NBC10 visited two such sites in Toronto, where neighbors have had mixed reactions but health officials have heralded them as a success.

Supervised injection sites are also being considered in other U.S. cities including Seattle, New York, San Francisco and Somerville, Massachusetts.

Philadelphia has the highest opioid death rate of any large U.S. city, with more than 1,000 deaths per year.