A 35-year-old woman died early this morning of a suspected drug overdose in Butler, authorities said.

Heather Grosskopf was pronounced dead at 3:30 a.m. at Butler Memorial Hospital where she was taken after her boyfriend discovered her unresponsive at her home on Maple Avenue.

An autopsy was planned later today, according to the Butler County coroner’s office, but results were not likely to be final pending the results of toxicology tests.

Butler police said Grosskopf’s boyfriend told authorities that he awoke about 2:30 a.m. and found her lying on the couch. He described her as “not breathing and turning blue,” said police Deputy Chief David Adam.

A Butler Ambulance Service crew arrived and did CPR before taking Grosskopf to the hospital.

Adam said police found an empty bottle of the prescription medication clonazepam, a drug used to treat seizures and panic disorder. The prescription had been filled Monday, police noted.