Retired Supreme Court Justice Sandra Day O’Connor, an unwavering voice of moderate conservatism and the first woman to serve on the nation’s highest court, died Friday. She was 93.O’Connor died in Phoenix, of complications related to advanced dementia and a respiratory illness, the Supreme Court said in a news release.Chief Justice John Roberts mourned her death. “A daughter of the American Southwest, Sandra Day O’Connor blazed an historic trail as our Nation’s first female Justice,” Roberts said in statement issued by …