Frances Kelsey was a Canadian doctor but she was quite famous in the United States. According to a report from the Globe and Mail, the doctor, who helped prevent one of the worst pharmaceutical disasters in U.S. history, died on Friday morning at age 101.

Dr. Kelsey was revered as a heroin for her involvement in the movement to oppose thalidomide, a drug promoted as a harmless sedative for pregnant women, in the 1960s. The drug was found to cause horrible birth defects in many cases.

Dr. Kelsey died less than 24 hours after she received the Member of the Order of Canada for her role in preventing the disaster. The gesture of recognition was certainly late coming, and was announced by the Canadian government this July.

Thalidomide was produced by the German company Chemie Grunenthal, and was approved for use in Britain, Japan, and Canada. Dr. Kelsey a novice examiner working for the U.S. FDA in the early 60s, insisted on obtaining hard evidence for the drug’s safety despite the company’s lobbying efforts for approval in the U.S.

The drug’s results in Canada were shocking – babies were born with missing limbs and internal organ damage, and soon reports of similar cases flooded in from around the world.

Dr. Kelsey’s outspoken call for rigorous testing of the new drug saved countless lives. She returned to Canada in 2014 where she lived with her daughter until her death. She is survived by her two daughters, a sister, and two grandchildren.