Sandra Day O’Connor, the first woman to serve on the Supreme Court, died at 93 on Friday.

She died in Phoenix, Ariz., “of complications related to advanced dementia, probably Alzheimer’s, and a respiratory illness,” according to a statement released by the Supreme Court.

“A daughter of the American Southwest, Sandra Day O’Connor blazed an historic trail as our Nation’s first female Justice,” said Chief justice John Roberts. “She met that challenge with undaunted determination, indisputable ability, and engaging candor.”

“We at the Supreme Court mourn the loss of a beloved colleague, a fiercely independent defender of the rule of law, and an eloquent advocate for civics education,” he added. “And we celebrate her enduring legacy as a true public servant and patriot.”

O’Connor was appointed to the high court in 1981 by Ronald Reagan and served until her retirement in 2006.