Montreal police have arrested a 55-year-old man after a death at a seniors' residence.

At 1:30 on Monday afternoon emergency workers rushed to the fourth floor of the Emilie Gamelin residence on Dufresne St. after being told a woman was not breathing.

Upon arrival, police found the 60-year-old woman in cardiac arrest. Attempts to revive her were unsuccessful.

Police arrested a 55-year-old man and he is considered a suspect in the woman's death. Police said one theory is that the man was the woman's boyfriend and that he smothered her with a pillow.

Though no motives or charges have been officially confirmed, police said they have determined the death was a homicide.

"The investigation is ongoing to determine the relationship between the man and the woman," said Const. Daniel Lacoursiere. "Also the investigators are meeting with possible witnesses to determine exactly what they saw."

Nursing home employee Rose Laure said the woman was a resident of the nursing home and was confined to a wheelchair.

"I knew her well," she said. "I was really startled when I heard the news. It's really bad."

Nursing home administarors declined to comment.