The woman who committed suicide using a toxic chemical on Tuesday at the Berkeley City Club, prompting a hazardous materials evacuation, was a former professor at UC Berkeley. She killed herself on her 71st birthday.

Sydney Kustu was a professor emerita in plant and microbial biology at Cal’s College of Natural Resources and a member of the prestigious National Academy of Sciences. She was born March 18, 1943, according to an official at the Alameda County coroner’s office, who said Kustu was a Berkeley resident.

Kustu was found deceased in a room at the City Club by a maid, according to an employee of the club, which also operates as a hotel. She had left notes for authorities warning them about the dangerous substance, according to the staffer.

Berkeley Police confirmed that the chemical used in the suicide was sodium azide.

Berkeley Police and Fire departments responded to a call of a “person down” at 1:56 p.m. Tuesday. A joint command that included UCPD spent several hours removing the hazardous material and making sure the building was safe. The club was evacuated and the 2300 block of Durant Avenue was closed to traffic and pedestrians until the evening.

The Berkeley Police Department said they treated the situation as a hazmat situation from the start, based off the warnings that were left behind. “We treated the situation with an abundance of caution given the nature of what we were dealing with,” said Berkeley Police spokeswoman Officer Stephanie Polizziani.

The Coroner’s Bureau official said a medical examination might take place Thursday to confirm Kustu’s cause of death. However it might be decided not to conduct the exam, he said, if it was determined it would cause “a risk of exposure of the chemicals to employees.”

Sodium azide is a rapidly acting, potentially deadly chemical that exists as an odorless white solid. When mixed with water or an acid, it changes rapidly to a toxic gas with a pungent odor, according to the Centers for Disease Control and Prevention. Sodium azide is best known as the chemical found in car airbags. It is also used as a chemical preservative in hospitals and laboratories, and in agriculture for pest control.

Kustu was recruited to Cal From UC Davis in 1987. In the fall of 2009, she told Breakthrough magazine, a publication of the College of Natural Resources, that science sustained and gratified her.

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“I do science because at one time it was forbidden fruit,” Kustu told the magazine. “When I was a child, men had professions; women were assistants. As a young woman I developed a passion for understanding how cells replicate themselves, how they integrate their parts into a self-reproducing whole.”

Kustu said there were many more female student scientists in her department than when she first arrived and the change was “heartening.”

This story was updated as new information became available.

Related:

Elderly woman commits suicide with toxic chemical at Berkeley City Club (03.18.14)

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