Grete Waitz, an Olympic silver medalist, World Championship gold medalist, two-time world record holder in the 3,000 meters and winner of a record nine New York City Marathons, died Tuesday after a long battle with cancer. Waitz, 57, passed away in a hospital in her hometown of Oslo, with her husband Jack by her side. She steadfastly refused to describe her type of cancer over the years, preferring to remain private.

For all her many accomplishments, the graceful, blond-haired Waitz might be best known for her first marathon. She accepted an invitation to run in the 1978 New York City Marathon, despite never having run more than 19 miles in a training run or 10 miles in a race. Fred Lebow, the founder of the NYC run, thought she would make a good pacesetter for the marathoners since she had been so successful in 3,000 meter races.

She arrived in the U.S. just a few days before the race and, because she was a late entry, she wasn't even listed in the official program. When she took over first place at the 20-mile mark, the public announcer said her number and not her name, famously announcing, "I don't know who she is."

Waitz went on to win that race in a new world record time of two hours, 32 minutes and 30 seconds, the first of three world records she set in the New York City Marathon -- in consecutive races. She won her final New York City Marathon in 1988 and finished fourth in her last competitive Big Apple race in 1990. She returned to race the 1992 NYC Marathon with Lebow, who at the time was in remission for brain cancer. Waitz told the New York Daily News the race was "the most emotional race" of her life. She and Lebow crossed the finish line holding hands; he died two years later.

As a racer, she inspired countless runners. As a woman, she broke barriers.

Amby Burfoot, of Runner's World, wrote of Waitz on Tuesday, "The world's most humble marathon superstar. She never, ever called attention to herself. But through her efforts and example, particularly in the New York City Marathon, which she won nine times, she turned the marathon into a worldwide, female-friendly urban phenomenon."

Waitz helped advance the cause of distance running long before she ever set foot in the States.

At 18, she participated in the first-ever women's Olympic 1500-meter race in 1972. Three years later, she ran in the first women's competitive 3,000 meter race, a distance for which she broke the world record twice. Waitz began running marathons on that fateful day in 1978, an unexpected victory that led to eight more New York Marathon wins over the next decade. She won gold in the marathon at the inaugural world championships in 1983 then competed in the first women's Olympic Marathon in 1984, earning a silver medal for Norway despite suffering from back spasms.

Throughout her battle with cancer, Waitz remained committed to the world of racing. In recent years, she rode in the pace car for New York City Marathon and often appeared at the New York Road Runners Club half-marathon race in her honor, "Grete's Gallop." In 2007, Waitz helped established the "Active Against Cancer" foundation in Norway, inspired by "Fred's Team," a similar organization that honors Lebow's legacy.

Since learning of her death countless runners and competitors have shared memories of her inspiring life.

To quote Burfoot, again, "Grete had such a long, wonderful career that we all have hundreds of memories of her. When I close my eyes, I see her pigtails swishing rhythmically like a metronome as she churned up First Avenue in New York. I think I will always see those pigtails.

"Grete Waitz was a pioneer, a pacesetter, a pathmaker. We cannot make too much of what she contributed to our sport. She gave and gave and gave, and asked nothing in return. Or maybe just this: That we should treasure every mile."

That's something everyone -- even those of us who will never have the guts to run a marathon -- can take to heart.