Nancy Reagan, the wife of President Ronald Reagan and an outspoken advocate of multiple social causes, has died. She was 94.

The Ronald Reagan Library and Foundation made the announcement Sunday morning. The cause of death was heart failure. She passed away at her home in Los Angeles. She will be buried in Simi Valley, California, next to her husband.

The former first lady took the lead during the 1980s on the White House's anti-drug program, telling millions of American children to "Just Say No" to drugs. When his administration ended and he began suffering more and more from Alzheimer's disease, she became highly protective of him, both personally and politically. Upon his death, she made Alzheimer's awareness and research advocacy a major life mission.

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