The five people who died of suspected fentanyl overdoses in a suburban Denver apartment included both parents of an infant who was found alive in the home, police said Wednesday.

The parents have been identified as Sabas Marquez, 24, and Karina Rodriguez, 28, Commerce City police chief Clint Nichols said. Their child is now being cared for by a relative, he said.

The other victims were identified by the coroner as Humberto Arroyo-Ledezma, 32, Stephine Monroe, 29, and Jennifer Danielle Cunningham, 32.

The cause of their deaths still needs to be confirmed by laboratory tests but authorities believe they died after taking cocaine laced with fentanyl on Sunday in the apartment in Commerce City, about 7 miles northeast of Denver.

Drug tests done there found an “overwhelming amount” of fentanyl and some cocaine, 17th Judicial District Attorney Brian Mason has said.

Fentanyl is an unpredictable and powerful synthetic painkiller that is blamed for driving an increase in fatal drug overdoses around the country.

It’s unusual to have so many suspected overdose deaths in one location, a spokesperson for the Drug Enforcement Administration’s Denver division, Steve Kotecki, said.

In September, comedian Fuquan Johnson and two other people died after suspected overdoses at a party in Los Angeles. Earlier this month, seven people died of suspected fentanyl overdoses within blocks of each other over several days in St. Louis.

The Associated Press