NEW YORK (CBSNewYork) — An 82-year-old Brooklyn woman was thought to have died from natural causes, but officials on Monday said her death was being investigated as a homicide.

As CBS2’s Jessica Schneider reported, the body of Myrtle McKenny was found at 11:42 a.m. Monday, Nov. 9, inside her sixth-floor apartment in a building on Powell Street, in the Carter G. Woodson Houses public housing development in Brownsville, Brooklyn, police sources told CBS2.

McKenny’s body was found face up on the kitchen floor by her home health aide, and she was pronounced dead at the scene, sources said.

Police initially thought it was all an open and shut case. Sources said the cause of death on the initial death certificate dated Dec. 1 and signed off by her doctor was “complications from hypertension and diabetes.”

But then, the Caribbean Funeral Services funeral home, on Nostrand Avenue in Prospect Lefferts Gardens, began preparing McKenny’s body for burial this past weekend. At that point, they found something alarming – stab wounds and broken ribs.

The New York City Medical Examiner’s office has now ruled that the cause of McKenny’s death was a stab wound to the neck and incise wounds to the right upper extremity with blunt force injuries to the head. She had been found to have three broken ribs and bruising to the face and neck.

The manner of death was homicide, the Medical Examiner’s office said.

Hypertensive and atherosclerotic cardiovascular disease were contributing factors in McKenny’s death, the Medical Examiner’s office said.

The victim’s apartment building is occupied mostly by elderly residents. Police late Monday had not given them any information about the homicide, leaving neighbors in a panic.

“They find out that they killed her. I said, ‘What?’” said neighbor Eliana Garcia. “That lady don’t bother nobody. She was a good lady.”

Sources said McKenny lived alone in the apartment.

Late Monday, police had not said who could have been responsible for the woman’s death, 1010 WINS’ Al Jones reported. Police also could not say why it took so long to determine that her death was a homicide and not natural.

The investigation continued late Monday.