Many died when the roof of a trade hall collapsed in Poland's southern city of Katowice late on Saturday.
Dozens remained trapped in the building, which was staging a pigeon exhibition.
About 100 were injured, some seriously, in the accident which officials believe may have been caused by the heavy snowfall.
At least 500 people were inside the building when the roof fell in, including children.
Shocked survivors were taken to hospital.
Rescue teams worked through the night amid freezing temperatures - but hopes of finding more survivors are fading.