According to the Emergency Situations Ministry, the building contained a gym where children were exercising.
One person was killed and 12 people, including six children, were injured.
A local doctor said, "According to children, the collapse followed an explosion that occurred while they were training. The children who were practicing kudo [a martial art] may still be inside the gym."
A spokesman for the local Emergency Situations Ministry said rescuers and firefighters were working at the site of the accident.
The ministry earlier reported that the roof of a fitness equipment shop had collapsed in Tyumen. The spokesman said the gym was on the second floor of the building, and a fitness center on the third.
This accident comes just over a week after the roof of a market collapsed in Kazan, the capital of the Volga republic of Tatarstan, injuring one woman, and three weeks after 66 people lost their lives in Moscow when the roof of an enclosed market caved in.
