Five people were discovered dead inside a Colorado apartment — where a 4-month-old baby was also found alive — after what police are investigating as a possible drug-fueled party that turned fatal.

The bodies of three women and two men were discovered inside a unit at the North Range Crossings Apartments on East 104th Avenue, Commerce City Police Chief Clint Nichols said, the Denver Post reported.

Another adult and an infant were found alive, he added.

A substance that “could be described as illicit narcotics” was found in the home, said Nichols, adding that further testing was planned.

“If it is going to be illicit drugs, they were very, very bad,” he said, according to the news outlet. “If it was drugs, no one was able to get to a phone and call 911 for a medical emergency.

“It happened pretty quickly — speculation on my part,” added the chief, who noted that it did not appear the victims died violently.

There also was no indication of any hazardous gases in the area, Nichols said.

Neighbor Ian Scott, 31, told the newspaper that he stepped outside when he heard screaming Sunday afternoon and saw a distraught woman holding a baby while talking on the phone.

Scott said he heard what sounded like a party with music and loud noise late Saturday.

Investigators were unsure if the infant’s parents were in the apartment and whether the five people found dead all lived there, Nichols said.

Per: NYP