It happened at the Freedom Ridge Recovery Lodge on Freedom Valley Circle in West Brandywine Township.
According to authorities, medics were called to the facility, which is a private residence used as a group home, around 2:15 p.m. Sunday.
The counselors were found unresponsive in separate bedrooms.
Authorities say it was the residents, who are recovering drug addicts, who tried reviving the counselors using naloxone, commonly known by the brand name Narcan, but were unsuccessful.
Both counselors were pronounced dead at the scene.
In their bedrooms, investigators say they found used needles and heroin baggies. Some had the Superman logo, while others had a skull and crossbones with the word "danger."
Toxicology tests for both counselors were positive for heroin and fentanyl. Authorities have recently warned of fentanyl, a substance much more potent - and lethal - than heroin.
"Anybody who sees baggies in the area with the Superman or 'danger' logo must be warned to stay away from these drugs. They appear to be heroin laced with fentanyl and are likely to kill anyone who uses them," District Attorney Tom Hogan said.
"We will not even let law enforcement handle them without special precautions because of the extreme danger of death or injury," he continued.
Hogan said this incident is the latest example of how bad the opioid epidemic has become.
"The staff members in charge of supervising recovering addicts succumbed to their own addiction and died of opioid overdoses," he
said. "Opioids are a monster that is slowly consuming our population."
An investigation into this case continues. Anyone with information is asked to contact Chester County Detective Ben Martin at 610-344-6866.
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