BOSTON (CBS) – A woman was found dead in an apparent suicide due to cyanide poising in her Brighton home on Tuesday.

A man found his 72-year-old wife unconscious in their Lake Shore Road home and two open bottles of cyanide on a table nearby.

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Sources told WBZ-TV the woman, a research associate at Dana-Farber Cancer Institute, left behind a suicide note indicating the presence of a chemical that would turn out to be cyanide.

WBZ-TV’s Beth Germano reports.

“It was powder form, they were doing CPR so it could have been some particles flying up in the air as they were doing chest compressions,” said Deputy Chief Steve Dunbar.

Investigators believe her position may have given her access to the poison.

WBZ NewsRadio 1030’s Bernice Corpuz reports.

“It appears during the course of employment she would have had access to the chemical,” said superintendent-in-chief Dan Linsky.

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Twelve people, including officers, firefighters, and civilians, were transported to St. Elizabeth’s Hospital as a precaution. They were later released, but not before the emergency room was placed into Code Black for a short time.

See: Cyanide Info From CDC

Vadim Grisgam, a neighbor, just saw the woman and her husband a few days ago.

“They got in the car to go, I believe, for a walk somewhere. It was all very peaceful and nice,” said Grisgam.

Cookie Weinstin, meanwhile, lives across the hall from the victim.

“It was disconcerting. I found out who it was, I was surprised. She was a lovely, lovely woman,” said Weinstein.

Crews said the cyanide scare is of no threat to the general public.

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WBZ-TV’s Beth Germano contributed to this report.