Japanese police are searching for clues into why a man set a Kyoto anime studio on fire, gutting the building and crushing the hearts of many anime fans around the world.

The man, screaming "You die!" stormed into Kyoto Animation on Thursday, doused it with a flammable liquid and set it on fire, killing 33 people and injuring 36 others. Witness accounts and reports Friday suggested the man had a grudge against the studio.

Police only have said the suspect, a 41-year-old who did not work for the studio, is from near Tokyo and is still hospitalized.

Media reports said Friday that the suspect told police he set the fire "because (Kyoto Animation) stole novels."

The attack shocked Japan and drew an outpouring of grief from anime fans.

Kyoto fire department official Kazuhiro Hayashi says firefighters found the largest number of victims on the top floor of the three-story building, including some who had collapsed on the stairs leading to the roof. Two of the dead were found on the first floor, 11 on the second and 20 on the third floor.

Japanese media reports said the suspect may have set the fire at the front door, forcing people to try to find other exits and slowing their escape.

The outcome makes the case the deadliest fire since a 2001 fire that killed 44 in Tokyo's Kabukicho entertainment district.

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