How it began
The fire broke out shortly after 10:30 Thursday morning. A man poured what appeared to be gasoline at the entrance to the studio of Kyoto Animation. He then set the liquid alight.
Eyewitnesses say the perpetrator yelled "shi-ne!" (die!) as he entered the building.
A nearby resident saw the studio shortly after the blaze started. She says she heard a thunder-like roar, and then saw flames gushing from the building.
Another man says about 10 people were on the ground near the building, and 7 to 8 others in the park. Their faces, hands and legs were black.
The suspect fled the scene, but was captured by police about 100 meters from the studio.
One witness says he was yelling that the studio had stolen his idea.
Police say the suspect is 41-year-old Shinji Aoba from Saitama City, just north of Tokyo. He has never worked for Kyoto Animation.
How the fire spread
The first floor of the building housed the office. The second and third floors were used as studios.
Police say 74 people, including employees of the company, were inside the building at the time of the fire.
They say they found many bodies on a staircase leading from the third floor to the rooftop. Police say many of the victims died of carbon monoxide poisoning.
One former employee said the studio was vulnerable because it was made mostly from wood.
Keizo Harafuji, a former police forensic scientist, says an explosion on the first floor blew out the windows. He says when a flammable substance ignites, it combusts and sends everything instantly up in flames, giving people little time to flee.
He says carbon monoxide must have also made it difficult for people to escape from the upper floors.
Looking for a motive
Kyoto Animation President Hideaki Hatta says the company has received e-mails with death threats.
He said he had been vigilant, but did not expect something like this to happen.
Kyoto Animation had told police about a threatening message posted on its website, and an investigation was underway. But police were unable to trace the message. Now they plan to investigate whether the suspect sent the threat.
Police say they haven't interrogated the man yet because he needed hospital treatment for serious burns.
They say they will wait for him to recover before they investigate his motives and other details of the suspected arson.
Kyoto Animation is also known as "Kyo-Ani."
It has produced popular TV and film animation series including "Suzumiya Haruhi no Yu-utsu" or "The Melancholy of Haruhi Suzumiya," and "K-On!"
The studio based its operations in Kyoto at a time when many studios were choosing Tokyo.
Museum of Kyoto curator Kiyotaka Moriwaki has been working with the studio. He says he always felt at home when he visited, and there was even a space for children to play.
Meiji University Visiting Professor Ryu-suke Hikawa is a researcher of animation. He says the studio built a strong brand name with its comprehensive abilities, high-quality work and sophisticated directorial and production techniques. He says it changed Japan's anime scene.
Reactions from abroad
Chinese state-media reported the incident as breaking news. Online, one commenter lamented the precious original pictures and materials that had been lost and described it as the Notre-Dame Cathedral of the animation world.
A US company that distributes Japanese anime set up a crowd-funding page to raise money to rebuild the studio. Within 24 hours it had raised $1million.