Gretchen Walsh swims during the Women's 100 butterfly finals on Sunday at the U.S. Swimming Olympic Trials in Indianapolis.

Gretchen Walsh swims during the Women's 100 butterfly finals on Sunday at the U.S. Swimming Olympic Trials in Indianapolis. / AP

INDIANAPOLIS — U.S. Olympic swim trials underway here have already made history with a new world record, seen major come-back stories play out and shown that legend Katie Ledecky, winner of seven Olympic gold medals, is still in top form.

The banger race so far at the Lucas Oil NFL stadium - converted for this event into a world-class swimming venue - was Gretchen Walsh's world-record shattering performance Saturday in the 100-meter butterfly.

Walsh, a 21-year-old Nashville native, captured a time of 55.18 seconds in a semifinal race, eclipsing the mark set by Sweden's Sarah Sjöström eight years ago at the Rio de Janeiro Olympics.

"I was probably the most shocked," Walsh said of her performance. "I was totally in awe, kind of surprised."

On Sunday, Walsh had to swim in top form again to capture the national championship in the 100-meter butterfly event and secure her first trip to the Olympic Games.

After past disappointments, big wins for Walsh, Foster

Walsh's breakout performance is one of the comeback stories taking shape at these Olympic trials.

Four years ago, she failed to make the U.S. team, while her sister Alex Walsh, another top American swimmer, traveled to Tokyo in 2021.

"That was a hard setback to process," said Gretchen Walsh.

Gretchen Walsh of the United States reacts after winning the Women's 100 Meter Butterfly Championship on Sunday in Indianapolis.

Gretchen Walsh of the United States reacts after winning the Women's 100 Meter Butterfly Championship on Sunday in Indianapolis. "I was probably the most shocked ... I was totally in awe, kind of surprised," she said after setting the world record on Saturday. / Getty Images

Carson Foster, who also fell crushingly short of making the Tokyo Summer Olympics, also won a place on the Paris team on Sunday.

Foster won the men's 400-meter individual medley finals, a race that includes freestyle, butterfly, backstroke, and breaststroke.

"There was still a fear because of what happened three years ago, coming to this meet" said the 22-year-old from Cincinnati. "It's a full-circle moment for sure."

Ledecky still a dominant force

One question put to rest here in Indianapolis is the status of American swimming legend Katie Ledecky.

Ledecky, age 27, has won seven gold medals for the U.S., a powerhouse run that dates back to the 2012 London Olympics.

She spent part of 2024 out on a book tour, suggesting her focus might not be on these swimming trials or the gauntlet ahead at the Paris Games.

But Ledecky won the women's 400-meter freestyle in a fiercely competitive field by nearly four seconds.

Katie Ledecky looks on after the Women's 400m freestyle final on Saturday at the U.S. Olympic Team Swimming Trials. The 27-year-old is the most dominant Olympic women's swimmer in American history and appears poised to add to her count of seven gold medals when she travels to Paris next month.

Katie Ledecky looks on after the Women's 400m freestyle final on Saturday at the U.S. Olympic Team Swimming Trials. The 27-year-old is the most dominant Olympic women's swimmer in American history and appears poised to add to her count of seven gold medals when she travels to Paris next month. / Getty Images

Asked by NPR if it was difficult to refocus for this competition, Ledecky laughed.

"I actually don’t think it is. I think it’s kind of the opposite for me," Ledecky said. "I enjoy this more and more each year. That's why I've been able to be consistent."

Organizers say this nine-day event, which continues through June 23rd, has already set another record of the largest crowd ever for a swimming competition.

Crews converted the Lucas Oil NFL stadium, home to the Indianapolis Colts, into a world-class Olympic-caliber swimming venue. On Saturday night, more than 20,000 fans turned out to see American athletes compete.

Crews converted the Lucas Oil NFL stadium, home to the Indianapolis Colts, into a world-class Olympic-caliber swimming venue. On Saturday night, more than 20,000 fans turned out to see American athletes compete. / NPR

More than 20,000 fans squeezed into the stadium Saturday night.

"I've never been to a swim meet like this with this excitement and crowd," said Lucy Weidert, who traveled from Spokane, Wash. to watch her grandson compete. "It’s been amazing."