Late Thursday, the Hungarian police said they had taken the captain of the much larger ship that clipped the Mermaid, identified as Yuri C., from Odessa, Ukraine, into custody and had formally requested his arrest.

It was the deadliest boating accident in Hungary in 75 years, and a particular blow to South Korea, which lost 304 people, including 250 high school students, in the Sewol ferry disaster in 2014.

Details: The boat was clipped from behind by a larger sightseeing ship and began sinking within seconds. Passengers were thrown into the fast-moving current, and many of those rescued weren’t wearing life jackets.

What’s next? A criminal investigation is underway. Hungary’s prime minister, Viktor Orban, said some 200 divers and medical professionals had been sent to the site. South Korea is sending an 18-member rescue team.