TOKYO — The attacker screamed “Die!” and set alight flammable liquid he had splashed around an anime studio in Kyoto, the police said, starting a blaze that killed 33 people Thursday in what appears to be Japan’s worst mass killing in decades.
Witnesses described scenes of horror at the studio, Kyoto Animation: a man hanging from a ledge as flames licked the walls; a pile of bodies on a staircase leading to the roof; a barefoot woman so badly burned that all bystanders could do was spray her with water as they waited for help.
The attack shocked a nation considered one of the safest in the world, and prompted a global outpouring of grief among the many fans of anime — a school of animation that has become synonymous with Japan.
The Kyoto police said the suspect was a 41-year-old man, and Japanese newspapers reported that he had been detained and hospitalized for burns.
Although Japan has a very low rate of violent crime, there are eruptions of rare but extremely violent attacks. The fire in Kyoto came just weeks after a man went on a stabbing rampage in a Tokyo suburb, attacking 17 schoolgirls, killing one of them and an adult.
Tokyo and its surroundings have suffered some of the worst violence. In 1995, members of a doomsday cult, Aum Shinrikyo, carried out a nerve-gas attack on the city’s subway system, killing 13 people and injuring thousands with sarin. In 2016, a mass stabbing at a center for people with disabilities outside Tokyo became the worst mass killing in Japan since World War II.
The death toll of the Kyoto fire was higher than in either of those attacks. Three dozen people were also injured in the blaze.
The attack touched a nerve among the Japanese public, and many poured out their grief on social media. The hashtag #prayforKyoAni had close to 260,000 tweets late Thursday evening. The studio has produced popular shows and movies, among them “The Melancholy of Haruhi Suzumiya,” “K-On” and “Clannad,” and has done contract work for the world-famous anime company Studio Ghibli.
There was little known Thursday about the man believed to have set the fire or his motives. According to NHK, the public broadcaster, he was hospitalized with burns and had told the police he had splashed flammable liquid at the studio building and set it alight.
Citing the Kyoto police, the Asahi Shimbun, one of Japan’s largest mainstream dailies, reported that the man had entered the building screaming “Die!” and then tried to escape, but collapsed on the street outside. He was captured by members of the studio’s staff.
Arson is rare in Japan, and experts quoted by NHK said Thursday’s fire was the worst case in decades. In 2001, 44 people died after a fire broke out at a crowded gambling club in Tokyo’s busiest entertainment district. It was investigated as arson, but the authorities could not confirm that the fire had been purposefully set.
The cultural reaction to Thursday’s fire reflected Kyoto Animation’s popularity among fans of anime, the category of Japanese cartooning that is a backbone of the country’s popular culture and one of its major soft-power exports.
Kyoto Animation — known as KyoAni among its fans — was founded by Yoko Hatta and her husband, Hideaki Hatta, in 1981, and most of the studio’s production takes place in the building that was the site of Thursday’s fire.
Whereas most major anime studios are based in Tokyo, Kyoto Animation chose to build its operations in a separate regional hub, one of Japan’s most popular cities among tourists, admired for its historical beauty.
The devastation at the studio, said fans, would rip a hole in the anime world.
“Would it get across to people who are not familiar with anime that the fire at Kyoto Animation studio is ‘a loss of culture,’ as if museums get destroyed by fire in an instant?” one wrote on Twitter.
Kyoto Animation distinguished itself by paying its workers salaries, rather than by assigning piecework, as many other studios do, said Susan Napier, an expert on Japanese animation at Tufts University.
Animation is “very hard work,” said Ms. Napier. “You’re usually overworked and underpaid and just killing yourself to get the product out, but Kyoto Animation was trying to be a more humane company.”
She said the studio was known for its high-quality series, combining science-fiction or fantasy elements with realistic plotlines and settings in high schools or real cities in Japan.
With roots going back to the early 20th century, anime has attracted an international following through artists like Hayao Miyazaki, whose feature “Spirited Away” won an Oscar in 2003, and Makoto Shinkai, whose movie “Your Name” was a global phenomenon, particularly in China.
Mr. Shinkai expressed support for the Kyoto Animation staff on Thursday. “Everyone at Kyoto Animation, stay safe,” he wrote on Twitter in a message that was recirculated almost 19,000 times.
Prime Minister Shinzo Abe also expressed his sympathy.
“Today, we had many casualties in a fatal arson attack that happened in Kyoto,” Mr. Abe wrote on Twitter. “It is so horrifying that I am at a loss for words. I’d like to express my deepest condolences to the victims. I offer my thoughts to those who have been wounded and pray for their recovery, by even one day.”
Witnesses who spoke to Japanese news outlets described grim scenes near the studio. According to The Mainichi Shimbun, a large daily, a woman in her 60s living near the building said she had seen a young woman, her entire body burned, screaming and running into a nearby shop, begging for help.
The witness said the woman was bleeding, her clothing torn and her feet bare. “It took a long time until the ambulance arrived,” she told The Mainichi. “All I could do was to spray water over her under the fire department’s instruction. She was eventually transferred to an ambulance.”
According to NHK, the police are investigating a report by a clerk at a gas station about a quarter mile from the studio who said a man in his 30s or 40s, wearing a red T-shirt and a backpack, bought about 10 gallons of gas at 10 Thursday morning. NHK reported that the man carried away the two gas cans on a hand cart, saying he would use them in a power generator.
NHK reported that an official at the Kyoto City Fire Department said that most of the 20 people who were found dead on the stairs that led from the third floor of the studio building to the rooftop were lying on top of one another right near the door to the roof. When rescuers reached the roof, the door was closed, though not locked.