OMAHA, Neb. — A severe storm packing strong wind damaged the Qwest Center and forced hundreds of swimmers practicing for the U.S. Olympic trials to evacuate the pools Friday.

Officials at the 7-year-old arena near downtown Omaha closed the building for the rest of the night after the afternoon storm blew through to check the extent of the damage. Superstar Michael Phelps and hundreds of other swimmers were herded into the hallways of the arena after a tornado warning was issued.

There was no structural damage to the Qwest Center. Repairs were under way and practices were to resume Saturday, according to USA Swimming spokeswoman Jamie Olsen.

Some swimmers and coaches crowded close to an outside door with a narrow window that revealed the chaos outside — furious wind, rain and debris scattering through the parking lot.

"I was going go check it out, but I figured I'd just sit down and rest," said two-time Olympian Erik Vendt.

Hail, heavy rain and wind of at least 50 mph tore through the city during the storm.

Water poured into parts of the Qwest Center, flowed down two sets of arena steps and onto the deck of the competition pool.

An elephant display for Mutual of Omaha's Wild Kingdom in the arena's lobby was flooded.

Outside, chunks of material from the building were scattered about. Some swimmers picked up the pieces and posed for pictures.