Two children have died and three other people were hospitalized after a tragedy in a rented apartment in a multi-story building in the Vostok district of Shymkent. The incident came to light after one of the victims called relatives and, with their last strength, pleaded for help, the website infohub.kz reports.

According to the KTK television channel's website, two families — two adults and three children — were renting a first-floor apartment in the building. Medics who arrived at the scene pronounced a 4-year-old boy and a 15-year-old girl dead. Three others were revived and sent to hospital.

"I arrived, but when I walked in I was horrified. In the living room my little sister was lying with her eyes open, she was unconscious. She was in a very bad way. Next to her, on the left side, lay her child. I thought he was asleep. But her daughter was crying and having convulsions," said Dilbar Saidkozhayeva, a relative of one of the victims.

"The patients were diagnosed with severe carbon monoxide toxicity. Because of the severity of their condition, both patients were taken straight to the intensive care unit, bypassing the emergency department," said Madina Yermakhanbetova, chief physician of the Shymkent Hyperbaric Oxygenation Center.

A 27-year-old woman and her three-year-old daughter remain under doctors' supervision: the child is still in intensive care, while the mother has been moved to a ward. The third survivor has been discharged home.

No one is yet willing to say exactly what happened in the apartment, but neighbors are convinced that natural gas is to blame. "The carbon monoxide came from the gas water heater, that's what we heard. We heard the gas water heater was old. The building's exhaust duct leading up there wasn't working, and that's why they were overcome by fumes," the neighbors said.

Gas company officials, however, have not confirmed this version so far. Specialists carried out all the necessary tests at the scene and found no gas concentration, but they did identify some violations.

"This building, frankly, is not designed for the installation of gas water heaters. Accordingly, installing a gas water heater is considered a violation. But I cannot say that this is exactly what caused it," said Nurbek Rakhmanov, head of the production and technical department at the Shymkent branch of QazaqGaz Aimaq.

After the tragedy, the apartment was sealed and gas was cut off throughout the building. Police and experts will establish the causes of the emergency.