BEIJING — Entering the Olympics, Katie Hoff swam the second-fastest time in the world in the 800-meter freestyle this year. Kate Ziegler is the reigning world champion in the event.

Neither will swim it in the Olympic finals Saturday after being eliminated in the preliminaries at the Water Cube on Thursday.

The stunning result ended a disappointing Olympics for both swimmers and marks the first time the USA will not medal in the event in a non-boycotted Games.

"I don't think many people bet on that," Ziegler said of the American shutout for the finals.

Hoff, 19, whose six-race Olympic program (including five individual events) drew comparisons with fellow Baltimore-area swimmer Michael Phelps, will go home with three medals but no gold. She won silver in the 400 freestyle, bronze in the 400 individual medley and 4x200 free relay and finished fourth twice.

She was unable to match her spectacular performance from the Olympic trials, when she won five events. Her Beijing times were slower in four of the five races.

"I think her expectations maybe to be like Michael were a little bit high at this point in her career, but she's still improving and she's had a spectacular year," Mark Schubert, U.S. swimming national team coach, said before the 800.

"The question is always going to be whether she bit off more than she could chew but the bottom line is she was the best person (on the U.S. team) in all the events we put her in," added Jack Bauerle, head coach of the U.S. women's team, after the race. "And we wouldn't have done it any other way."

Hoff labored noticeably in the final 100 meters of the 800 freestyle, finishing third in her heat and placing 11th overall with a time of 8 minutes, 27.78 seconds — about 8 seconds slower than her time in the trials finals. She didn't speak to reporters after the race.

"She didn't look like herself during the race," said Phelps, who used to train at the same Baltimore swim club as Hoff. "I'm not sure why or how, but she trained really well leading up to it. I guess this will be a big learning experience for her. She's someone who, when she has something like this, you can guarantee she's going to be better next time."

"Everyone saw the last 100 and she gave everything she had," Bauerle said. "She was just pretty much out of gas. She did a heck of a job for us here."

The burnout came a few hours after Hoff's best swim of the Olympics, the anchor leg in the 4x200 free relay. She had the best split of the American women, but the USA was far behind when she hit the water and finished third.

"I'm not sure we would have medaled in the relay without Katie on the end," Bauerle said.

Ziegler, 20, who broke Janet Evans' long-standing record in the 1,500 free (which isn't swum in the Olympics) last year and won the 800 at the 2007 world championships, failed to qualify for the finals in two events at the Games.

"Some days your body just doesn't work," she said, adding that she felt "amazing" during the training camp in Palo Alto, Calif., after Olympic trials but lost the edge when the team moved to Singapore before coming to Beijing.