Her daughter Carrie Cuneo said Thursday she died at her San Rafael, Calif., home of complications of Alzheimer's disease on June 26, weeks before the games returned to the city where she won international acclaim.
Born in 1926 in San Francisco, Curtis started her swimming career at the age of 12. She didn't get to compete in the Olympics until they resumed in 1948 following a 12-year hiatus due to World War II. By then, she had already won eight national titles and broken 18 U.S. records.
"I was lucky that the Games restarted at a time I was still competing. There were awfully good swimmers before my time, and it was too late for them," Curtis told The San Francisco Chronicle in 2008.
It was Curtis' only Olympics. She took medals in all three events she competed in: gold in the 400-meter freestyle, gold in the 4x100-meter relay and silver in the 100-meter freestyle. She would go on to become a paid athlete, participating in water shows and competing in U.S. masters championships. She was elected to the International Swimming Hall of Fame in 1966.
"She swam in the Olympics in her prime, and it's hard to revisit that," Cuneo said.
Curtis married Gordon Cuneo a year after the Olympics, and they had their first of five children in 1950. Her daughter recalls Curtis' modesty about her success and fame, never discussing her career unless asked.
"We came across the medals going through the drawers and asked 'What's this? It's pretty. Can I play with it,'" Cuneo said.
In the early 60s, Curtis moved to San Rafael and started a swimming school, where she coached for 25 years. Her students included Olympians Rick DeMont and Ben Wildman-Tobriner.
Curtis stopped swimming several years ago, but took up water aerobics and water walking, her daughter said. Curtis' husband died in 2010. She is survived by four children.