A heating system breakdown has flooded the streets of Russia’s third-largest city of Novosibirsk, authoritiessaid Thursday, with over 100 apartment buildings left without heat.Video published by local news outlets showed steaming-hot water engulfing streets and entire blocks of residential neighborhoods.“Residential buildings and public facilities in the Leninsky district were disconnected from heating and hot water to fix the defect in the heating main,” Novosibirsk’s city government said in a statement.Overall, officials said 104 apartment buildings and private homes, as well as 13 state-owned buildings, includingschools and kindergartens, were left without heating.Acting Novosibirsk Mayor Oleg Klemeshovsaid a total of 237 buildings were disconnected from central heating systems, according to the city’s news website NGS.ru.Utilities provider Siberian Generating Companysaid the damaged heating main — which was still being repaired as of mid-Thursday — was built in 1974.Authorities promised to fix the damage by late Thursday, when temperatures are expected to dip below minus 20 degrees Celsius.Russia’s Investigative Committee, which probes major crimes,launched a criminal investigation into possible safety violations.The flooding in Novosibirsk came a day after asimilar heating main accident and flooding in Vladivostok.Unprecedented heating outages have been multiplying in Russian cities since the New Year holidays, with bone-chilling weather across much of the country compounding the severity of what is quickly growing into a major crisis for the authorities.