The snow-covered roof of an indoor swimming pool collapsed onto parents and children in a Ural Mountains town, killing 14 people, including 10 children, in a deluge of concrete and metal, officials said Monday.

The accident occurred Sunday in the town of Chusovoi in the Perm region, about 750 miles east of Moscow. Emergency Situations Ministry spokesman Viktor Beltsov said that 14 people had been killed and 11 people remained hospitalized with injuries.

The 10 dead children ranged in age from 3 to 13. Most visitors were parents with children, basking in the warm water as a respite from biting frost and snow outside.

"We were swimming leisurely close to each other," Roman Guzenko, a bruised survivor, said from his hospital bed in remarks broadcast by Russian television. "It collapsed in a fraction of second. We didn't even understand what happened."

Guzenko's wife survived the accident with grave injuries, but their 4-year-old son was killed.

Investigators were looking into whether fluctuations in temperature or a recent heavy snowfall could have caused the roof to collapse.

"The quality of concrete was very poor," said Ivan Kumanyov, the head of the local branch of the Emergency Situations Ministry.

He said that the steel and 45 slabs of concrete fell on the swimmers, covering an area of about 480 square yards.

Rescuers using heavy cranes worked for more than 15 hours to remove all the bodies.

The incident echoed a similar collapse at a popular Moscow water park in February 2004, in which 28 people died and more than 100 others were injured.

Channel One television said the pool in Chusovoi, which was built 13 years ago, had been checked for safety and declared safe after the Moscow water park accident.

Local authorities said that Tuesday would be a day of mourning for the victims.