The tragic dry ice pool incident occurred on February 28, 2020, during a 29th birthday celebration for Russian Instagram influencer Ekaterina Didenko at the Devyaty Val pool complex in Moscow. Party organizers dumped 55 pounds of dry ice into an indoor swimming pool to create a dramatic, foggy visual effect.
Guests who had just exited a hot sauna jumped into the pool to cool down.
Dry ice is solid carbon dioxide (CO₂). When it hits water, it rapidly sublimes into a large volume of heavy gas. Because the pool was indoors and lacked adequate ventilation, the dense gas pooled directly over the surface of the water, displacing the oxygen. Swimmers immediately began to choke, suffer chemical burns, and lose consciousness. Two guests, both 25, died at the scene. The influencer’s husband, 32, who actively unloaded the ice, later died in the hospital. Multiple other guests were hospitalized with severe carbon dioxide poisoning and chemical burns.
Following the incident, the Russian Investigative Committee opened a criminal case to investigate the deaths caused by negligence.