AUBURN — Bonnie Waisanen on Friday didn’t know if she should be angry or sad. It turns out she was a little of both.

Waisanen was in her first-floor apartment at 108 Mill St. on Thursday night when she learned that her friends in the apartment above had fallen unconscious.

She rushed upstairs and tried to help, but for at least one of the victims, it was too late.

“I began CPR while on the phone with 911,” Waisanen said Friday, “but there was only one of me and two non-breathing people.”

Ultimately, one of them, 49-year-old Deidre Hall of Livermore, died of a suspected heroin overdose. Kevin Cooper, 50, of Auburn, was revived but he was in intensive care Friday at a Lewiston hospital.

While police and drug officials investigated the overdose, Waisanen remained both angry and anguished.

She knew Cooper as “Coop,” she said, and Hall as simply “D.”

“I just met her about six months ago, when she and Coop started dating,” Waisanen said. “She was from the south and made the best fried chicken I ever had. She was planning a three-week trip back home to Virginia, with Coop, to visit her friends and family, and she was very excited about that.”

She described Cooper as an easygoing guy who loves to play pool and who loves his dog, Buddy.

“Super nice guy,” Waisanen said. “Quiet, mostly, but in the close circle of friends he has, he is held dear.”

Cooper’s dog is staying with Waisanen on the first floor while Cooper clings to life at Central Maine Medical Center.

The overdose ended one life and left another in chaos. Drug officials say that’s what heroin addiction does, and especially at a time when the contents are largely unknown from batch to batch.

“You don’t know what the source of supply is, you don’t know where it came from,” Maine Drug Enforcement Agency Supervisor Matt Cashman said. “You don’t know what it’s cut with or how many hands it’s gone through. Each time you put a needle in your arm, it’s like playing Russian roulette.”

The problem, drug officials said, is that dealers who supply the drug — typically trafficked from Massachusetts, New York and Connecticut — often cut it with other substances.

“You don’t know what the drug is, or what the cut is,” Cashman said. “Whether it’s fentanyl, whether it’s pure fentanyl, whether it’s heroin, whether it’s a mixture… You don’t know what the concoction is.”

The results have been deadly. Over the past few years, the number of drug overdoses has spiked sharply across the state. Cashman said they see it all over the tri-county area — heroin addiction is not just a city problem.

Auburn police are investigating the double overdose on Mill Street with the assistance of the MDEA. Drug officials say the cause of death and details about the heroin mix that was ingested will not be known until an autopsy is performed and toxicology reports finalized.

At the request of his family, no further information was being released on Cooper’s condition Friday night at CMMC. He was listed in critical condition the night before.

For Waisanen, it’s particularly infuriating that people know all about the uncertainty of heroin, yet the epidemic continues. She had all of that in mind Friday as she mourned her friends and mulled the needless nature of what had happened in the apartment above her own.

“I guess I’m more angry right now,” she said. “I can be sad later.”