This was reported to TASS by the press service of the Investigative Committee.

"The preliminary investigation established that the likely cause of the fire was a short circuit in one of the chambers where the boiler worked, which sparked at the time of operation and fell on the mattress of one of the patients," the ministry said.

The Chairman of the Investigative Committee Alexander Bastrykin put the course of the check on the fact of the fire under personal control.

According to the director of the regional health department Vasily Tubashov, the cause of the death of one of the patients was not a fire, but a coronavirus infection.

"The patient, who is often mentioned in the media, died of coronavirus infection, was in the intensive care unit, at 21:50, death was pronounced, taking into account the intensive care measures that were carried out before that for half an hour," Tubashov said.

Earlier it was reported that the prosecutor's office of the Yaroslavl region organized an inspection on the fact of a fire in clinical hospital No. 3.