The death toll rose steadily through the early hours of Sunday as rescuers dug through the building following its collapse at around 5:30 p.m. (1630 GMT) Saturday in the city of Katowice.
Jaroslaw Wojtasik, spokesman for the fire department in Katowice, insisted the hundreds of rescuers would press on in hope of finding survivors.
But more than eight hours had passed since the last person was pulled alive from the twisted ruin of corrugated metal.
"From experience, we are making our way toward niches or hollows, or some protected places where there could still be people alive," Wojtaski said. "As long as there is hope and there is faith, then we will search the whole time, nobody will rest."
The hopes of finding survivors faded early Sunday after no one had been found alive since 10 p.m. (2100 GMT) Saturday in 1 Fahrenheit cold.
These actions in a way have come to an end and we are bringing out corpses," said Katowice fire chief Kazimierz Krzowski said at 4:30 a.m. (0330 GMT).
It wasn't clear how many more victims might still be under the building. Up to 500 people were in the exhibition center on Saturday when the roof fell in. People trapped in the wreckage used cell phones to call relatives or emergency services and tell them where they were.
Crumpled birdcages were scattered inside the building near the entrance, and dozens of white and brown pigeons perched on the twisted rafters, their feathers fluffed against the cold.
Witness Franciszek Kowal said he was inside the building when he saw the roof starting to buckle and he escaped to a terrace, then jumped about 13 feet to safety.
"Luckily nothing happened to me, but I saw a macabre scene, as people tried to break windows in order to get out," Kowal told The Associated Press. "People were hitting the panes with chairs, but the windows were unbreakable. One of the panes finally broke, and they started to get out by the window."
An unidentified woman with bandages around her head, a bloodied chin and scrapes on her face told TVN24 from her hospital bed that she feared one of her friends was dead.
"I heard a snap like breaking matches as the roof fell on everybody. Then I heard an unbelievable scream, and then I tried to escape like everybody else," she said.
"Something fell on me, I turned around, somebody stepped on me, but on my knees I was able to get out," she added. "I still don't know where some of my friends are and I haven't had any contact with them, most likely one of them is dead."
Hundreds of fire fighters and police officers and mine rescue teams from around the region were brought in to help.
Prime Minister Kazimierz Marcinkiewicz flew in by helicopter and spent about 15 minutes looking over the site with rescue crews.
The 110,000 square-foot hall in the Bytkow district of the city had been hosting the exhibition, which opened Friday.
The "Pigeon 2006" fair was made up of more than 120 exhibitors, including groups from Belgium, the Netherlands, Germany, Ukraine and Poland, according to the fair's Web site. The fair was devoted to pigeon racing, a sport in which homing pigeons are released and race home using their sharp sense of direction.
Katowice, some 200 miles south of Warsaw in a mining region, has been hit with the same heavy snow this winter that has been plaguing much of eastern and central Europe.
On Friday, snow caused a town hall's roof to collapse in the southern Austrian town of Mariazell, though no injuries were reported.
On Jan. 2, the snow-covered roof of a skating rink collapsed, killing 15 people, including 12 children in the German Alpine spa town of Bad Reichenhall.