On Wednesday night, a boat carrying over thirty South Korean tourists and two Hungarian crew members sank after it collided with another vessel on the Danube River. Seven have been rescued, seven were found dead, but 21 are still missing, and a search operation is still in progress.

Since the seven who were rescued were not wearing life jackets, it’s unlikely that those still missing are wearing them. Powerful currents on the river are believed to be one of the reasons for the accident, as heavy rainfall had made those currents stronger than usual. A criminal investigation has also been launched, as it’s unclear which vessel was responsible for the collision, or whether it could have been prevented.

The accident occurred right near Budapest’s most recognizable landmark — the parliament building — and involved a two-deck sightseeing boat called the Hableany. CCTV footage reveals that the Hableany collided with a larger tour boat, the Viking Sigyn, near the Margaret Bridge. According to police, the boat sank just seven seconds after the collision.

The cause is still unknown, but Imre Horvath, head of the Hungarian National Shipping Association, said he believes human error is to blame.

Although rescue efforts continue with boats, spotlights, divers, and radar, as time passes, the strong currents make it less likely that survivors will be found. For now, boat traffic has been halted on the Danube south of Budapest.

While still holding out hope that more survivors will be found in the river, the South Korean ministry has announced that counseling will be provided for families of the victims.

H/T: BBC