Three people are dead and four have been hospitalized after police responded to a call near South Side Works in Pittsburgh Sunday morning. Police said the deaths and injuries appear to be drug related.

A man was found on 26th and Carson streets at 3:20 a.m. and was taken to Pittsburgh Mercy hospital. One man, who later died, was found in the elevator at South Side City Club Apartments at 4:01 a.m. Two men were found dead in an apartment there at 5:38 a.m., and three others there were taken to Mercy, said Wendell Hissrich, the city’s director of public safety.

The four surviving victims were hospitalized — three are stable and the other is in serious-to-critical condition. All victims were male, were middle-aged and wearing orange wristbands, police confirmed.

Jason Lando, commander of the city’s narcotics division, said the symptoms experienced by the victims appears to be overdose related. He would not say which drug or combination of drugs led to the suspected overdoses.

He said several events gave out orange wristbands Saturday night. But, he said, police believe the victims left the venue that had the writstbands and went to another location to do the drugs. They then overdosed at the apartment building.

"We have no indication there was a party (at the apartment)," Mr. Hissrich said.

Commander Lando said investigators are at the hospital speaking with the surviving victims to piece together what happened.

“To be clear, this was not a case of a tainted drug being passed around or distributed in large volume at a large venue which could have affected even more people. It appears to have been isolated to a single location,” the Pittsburgh Department of Public Safety said in a statement. “However, police are concerned about a tainted, potentially deadly batch of drugs in the community.”

In a statement, a public relations firm that represents the apartment building said the victims were not residents of the building.

“We express our deepest sympathies to the families and friends of the affected individuals and send our thoughts and prayers to those who were transported to the hospital,” the release said.

“It is important to note that the individuals that were involved in the incident were not residents of our community,” the release said. “These were acquaintances of a good standing resident, who apparently was not in the apartment at the time the individuals were found.”

The statement added: “It is our understanding that the group had attended an outside event where they may have consumed a toxic substance before returning to the apartment.”

Pittsburgh EMS checked the building's air quality and have found no danger to the building's other residents, Mr. Hissrich said.

The building is owned by Southside Works City Apartments LLC, which has an owner mailing address based in Southfield, Mich., according to Allegheny County property records. The building contains more than 40 units and is valued at $25.8 million.

Mark Winters, a spokesman for the management company, said access to the building is keyless and residents wave a key fob to gain entry.

He said he didn’t know how the men were able to enter the building and the resident’s apartment. “But when they arrived, the resident wasn’t there,” he said.

This is a developing story. Check back for updates. The Associated Press contributed to this report.