Joan Rivers' Clinic, Yorkville Endoscopy, Under Investigation

Remembering Joan Rivers

Sept. 4, 201403:22

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The Manhattan clinic where Joan Rivers stopped breathing while undergoing an outpatient procedure on her vocal cords on Aug. 28 is under investigation by the New York State Department of Health, NBC News has learned.

Rivers was at Yorkville Endoscopy when she went into "respiratory or cardiac arrest," according to the New York Fire Department and was transported to Mount Sinai hospital. A spokesman for the Health Department told NBC News that officials are "Investigating the matter."

Physicians at New York Gastroenterology opened Yorkville Endoscopy in 2013.

The 81-year-old comedy legend died on Thursday afternoon at Mount Sinai in New York City, according to her daughter Melissa Rivers.

"My mother’s greatest joy in life was to make people laugh," Melissa Rivers said in a statement. "Although that is difficult to do right now, I know her final wish would be that we return to laughing soon."