R.I.P. Kazuki Takahashi, creator of Yu-Gi-Oh!

Kazuki Takahashi, the Japanese manga artist who created Yu-Gi-Oh!, was found dead on Wednesday. He was 60 years old.

According to NBC News, Takahshi’s body was discovered by the Coast Guard about 1,000 feet offshore from Okinawa Island, Japan. He was wearing snorkeling equipment when he was found, and officials told the outlet there were “damages to his body which looked like they were caused by some sort of marine animal.” An abandoned vehicle at a nearby beach rented by the artist helped to confirm his identity. He had been traveling alone.

Takahashi began his career as a manga artist in the ’80s, but his popularity exploded with the publication of Yu-Gi-Oh! in 1996. The original run of the manga ended in 2004, and ultimately ended up spawning a multimedia empire that includes a long-running anime series and a number of film and video game adaptations.

He also had a hand in creating the ultra-popular trading card game that stemmed from the manga. The game was such a resounding worldwide success that in 2009 it was certified by the Guinness Book of Records as the trading card game with the world’s highest sales.

Following the conclusion of the manga, Takahashi continued to work in a supervisory role with Yu-Gi-Oh! as well as working on new projects, like 2018’s The Comiq. In 2015 he was honored with Comic-Con International’s Inkpot Award, “recognizing an individual who has made outstanding contributions to comics, science fiction and fantasy, film, television, animation, and fandom” (per Variety). Most recently, he published Secret Reverse, a comic starring Iron Man and Spider-Man, under Marvel and Viz Media.

Following news of the artist’s death, the website for his agency Studio Dice went dark with the message, “This site is under pause. Resumption time is undecided.” Officials are still investigating the exact cause of death.