Five people, including one child, were killed in the Russian city of Perm on Monday when a hot water pipe exploded in the night and flooded a basement hotel room with boiling water.
At least three other people were taken to hospital with burns after the incident in the Mini Hotel Caramel, which is located in the basement of a residential building, the region's investigative committee said.
A doctor treating the victims, Andrei Babikov, said a 33-year-old woman had burns covering 35% of her body. Two men aged 28 and 35 were in a less serious condition.
Regional governor Maxim Reshetnikov said it was a "terrible accident."
"We will conduct the necessary checks with law enforcement and monitoring services," he said on Instagram. "Special thanks go to the rescue workers, who themselves received burns in pulling people out."
Video posted on social media showed thick steam billowing out of the hotel's entrance in the early hours of Monday morning, with emergency services in attendance.
Investigators opened a criminal investigation to establish whether the deaths resulted from negligence.
The RIA news agency reported that the heating pipe that exploded had been in operation since 1962 and had broken repeatedly in the past, citing a source in the Perm emergency services.
"There were no victims in previous explosions," the source said. "It was not replaced, only repaired."