Kyoto, Japan - Smoke spread so quickly through a burning Japanese animation company that a majority of victims who had tried to flee through a rooftop door were unable to open it before perishing, Japanese media said on Monday.
The attack at Kyoto Animation on Thursday, in which a man shouting "Die!" poured a bucket of gasoline at the entrance to the building and lit it, took 34 lives and ranks as one of the worst mass killings in Japan for decades.
Of those who died, 19 were found piled on top of each other on a stairway between the third floor and a door to the roof, with some early reports suggesting it could not be opened from the inside.
But police quoted by NHK national television on Monday said investigations had shown that while the door could be opened from the inside, smoke from the blaze had apparently spread so fast that the victims were overcome before being able to do so.
Kyoto police said on Monday that of the 26 people whose autopsy results have been released, 20 burned to death, three died of carbon monoxide poisoning and two suffocated. The cause of death of one remained undetermined.