Moscow's Mayor Yuri Luzhkov has said there is no hope of finding more survivors in the rubble of a water park that collapsed on Saturday.
Hundreds of people were in the building at the time
At least 25 died and more than 100 were injured when the giant glass roof of the Transvaal park crashed down.
A criminal investigation has been launched as prosecutors suspect faulty construction or maintenance of the two-year-old complex could be to blame.
Clearing work is continuing at the complex in freezing conditions.
The park was packed when the roof caved in, showering shards of glass on those below; terrified survivors fled in their swimming costumes.
Many others are feared trapped in the debris. Emergencies Minister Sergei Shoigu said 17 people were still unaccounted for.
Initial reports suggest poor building work or heavy snow piled up on the roof might have caused it to collapse.
Moscow prosecutor Anatoly Zuyev said officials would investigate whether negligence was to blame.
He said park managers, builders and architects would all be questioned.
Mr Luzhkov said earlier there was no evidence a blast had caused the disaster and that there had been no snow on the roof.
Twisting water slide
Nearly 1,000 rescuers with sniffer dogs rushed to the leisure complex in the capital's south-west immediately after Saturday's incident.
They worked through the night, stopping at regular intervals to listen for voices in the rubble. They dug out more bodies on Sunday.
Moscow's biggest water park
Has artificial river, bowling alley, sauna and solarium
Four children were among those killed, the Emergency Ministry said.
But with temperatures as low as -15C (5F) officials expect the death toll to rise.
"There is no hope survivors can be found," Mr Luzhkov told Russian Channel One television later on Sunday, but said efforts would continue through the night to clear the scene.
Russian television footage from inside the park showed that beams - apparently made of concrete - had collapsed onto the pool's twisting water slide.
More than 800 people were in the leisure complex when its vast roof caved in. Over 300 are thought to have been in the swimming pools.
'Everything in blood'
Witnesses spoke of their horror and panic when they heard the cracking sound of the roof caving in.
"There was a loud noise," one of the witnesses told Russia's Channel One television.
"Everybody started to run. I started to run. All of the roof over the water zone collapsed."
Another witness, Roman Yazymin, told the Associated Press news agency that he was sun-tanning in a solarium on the upper floors of the complex when he heard a loud noise and the crash of shattering glass.
"Everything was in blood," he said as he walked through the complex to retrieve his clothing.