OMAHA, Neb. - Michael Phelps' grueling schedule in the U.S. Olympic swimming trials has gotten a bit easier. He won't be competing in the 400-meter freestyle.

The event was one of nine Phelps had entered during the eight-day meet that begins today. But his name was absent from the 400 freestyle heat sheets released last night. The move wasn't unexpected because Phelps' coach, Bob Bowman, had hinted that he would drop the event.

Phelps still will be in action on opening day, competing in the 400 individual medley, in which he owns the world record. He will be challenged by Ryan Lochte, who entered a staggering 11 events but isn't expected to swim them all. They will swim the 400 IM preliminaries in the morning, with the final in the evening.

Among the roughly 1,200 participants in the trials are the Crippens of Conshohocken and Germantown Academy (Fran, 24; Claire, 19; and Teresa, 18).

Hundreds of swimmers resumed practice at the Qwest Center's two pools yesterday, while repairs were made to the arena after damage by a severe storm a day earlier.

Powerful winds tore siding off the front side of the building, and heavy rain overloaded the arena's main drains. A 12-inch pipe in one section was blown out, causing water to cascade down steps in the seating area and onto the pool deck.

"We're not pretty, but we're functioning," said Roger Dixon, president and chief executive officer of the seven-year-old arena. "We're very lucky we had no injuries."

About 600 swimmers, including Phelps, were ordered out of the competition and warm-up pools late Friday afternoon and sent to the building's interior hallways and lower floor. About two hours later, after the storm had passed, the building was cleared and practice was canceled for the rest of the night.

The water in both temporary pools was unaffected, Dixon said.

Much of the debris outside the arena had been cleaned up yesterday, when the building's electrical system was still being assessed, Dixon said. Ceiling panels damaged in the southeast section were being replaced.