Two people died and another ended up in the hospital Sunday afternoon after a string of suspected overdoses in a 2½-hour period in Butler, authorities said.

It’s believed opioids — likely heroin — are to blame for the two deaths.

Butler police and city firefighters were first called shortly before 2:30 p.m. to a home in the 200 block of North Bluff Street where a 31-year-old woman was reportedly unconscious and turning blue.

The woman, Marissa A. Shipley of Greensburg, Westmoreland County, had been living at the home that authorities described as a sober-living residence or half-way house.

Another person living there found Shipley unresponsive and called 911, reporting the apparent heroin overdose. Police later recovered two hypodermic needles — one empty and one filled with brown liquid, believed to be heroin.

By the time emergency crews arrived, Shipley was already dead. Butler County Deputy Coroner Larry Barr pronounced her dead about 3 p.m.

An autopsy was conducted but a cause of death is still pending the results of toxicology reports.

A little more than an hour later, crews were called to a home on East Boyd Avenue for another overdose that proved fatal.

A relative found Joshua S. Dapper, 35, of Butler unconscious and called 911 about 3:40 p.m. The caller reported Dapper had overdosed and was “cold to the touch,” authorities said.

He had a “very faint pulse” when crews arrived, according to the Butler Fire Department. Paramedics began cardiopulmonary resuscitation that continued while Dapper was rushed by ambulance to Butler Memorial Hospital.

He was pronounced dead at the hospital that evening. An autopsy was performed and investigators are awaiting toxicology reports before listing a cause of death.

The third overdose call Sunday came in just before 5 p.m., authorities said. Emergency crews were sent to a home in the 300 block of Center Avenue for the report of a 20-year-old woman who had overdosed.

There, the fire department said, rescuers found the alleged victim, Karlee A. Quinn of Butler, conscious and “running around.”

She was reportedly taken to Butler Memorial Hospital for treatment. The type of drug she is suspected of overdosing on was not known.

But the day before, police were called to the same home where they believe Quinn had deliberately taken an overdose of Ritalin, a prescription drug used to treat attention deficit hyperactivity disorder.

Following the call about 7 p.m. Saturday, she was taken to Butler Memorial.

Meanwhile, on Monday morning, police and rescuers were called back to the same home on East Boyd Avenue where they found Dapper the day before.

This time, James O. Watkins, 32, Dapper’s brother who also lives there, suffered an apparent heroin-related overdose about 8:30 a.m., police said. Medical crews used the anti-opioid drug naloxone to revive him. He refused further medical treatment.