A fire broke out in a women's ward of a drug treatment hospital early Saturday, with heavy smoke killing 42 people, some while they slept and others whose attempts to flee were thwarted by metal grilles blocking escape routes, authorities said.
Russia's chief fire inspector, Yuri Nenashev, said he was "90% certain" the fire was caused by arson. But Moscow city prosecutor Yuri Syomin said investigators were looking into other possibilities.
About 160 people were evacuated from the five-story Hospital No. 17 in south Moscow, said Fire Department spokesman Yevgeny Bobylyov. He blamed hospital workers for not being fast enough in reacting to the fire and evacuating people.
The fire started in a cabinet in a corridor on the hospital's second floor.
"One staircase was blocked by the fire and the other was blocked by a metal grille that firefighters had to remove," said Irina Andrianova, a spokeswoman with the Emergency Situations Ministry. The barred windows were locked.
Deputy Minister Alexander Chupriyanov said that "judging by the placement of the bodies, they really tried to get out."
Nenashev said fire inspectors had visited the hospital twice this year and recommended it be temporarily closed because of fire safety violations, but no action was taken.
Bobylyov also criticized hospital officials for not calling the fire department to report the blaze sooner. He said the fire was extinguished within an hour of the first call for help.
It was the worst fire to break out in Moscow in three years. In November 2003, a predawn fire swept though a dormitory for foreign students who had been quarantined for medical checks, killing 36 and injuring nearly 200. Many were trapped behind permanently locked exits, causing some to leap from the building, which was also five stories.