On the rainy night of May 29, 2019, at 9:05 pm the 135-metre (443 ft) Viking Sigyn collided with Hableány from behind under the Margaret Bridge near the Parliament Building.

At 9:05 pm local time on May 29, 2019, the River Cruise Hableány was rammed amidships portside by Viking Sigyn while crossing under the Margaret Bridge near the Parliament Building on a 457-metre-wide (500 yd) section of the Danube.

[14] The rescued passengers had not been wearing life vests, while another South Korean tourist said that cruise boats arranged by tour companies often lacked them.

[15] Police and ambulance services arrived at the collision site approximately ten minutes later at 9:15, shortly after being notified of an overturned boat.

[16] Search and rescue efforts began immediately, with several spotlights brought to the site and over 200 divers and medical personnel arriving within hours.

[16][12] The fast-moving water, reaching speeds of 9 to 11 kilometres per hour (5.6 to 6.8 mph), caused limited visibility underwater and prevented divers from searching inside the wreckage of Hableány to recover more bodies.

[14] The first major diving operation began five days after the collision and ended with the discovery of an eighth body that was recovered by Korean divers.

[26] Later that night a police statement explained that the body of a female passenger had been retrieved from the Danube in the afternoon, close to the site of the accident, and another had been found and identified at Ercsi.

The search team were continuing to locate the bodies of three South Korean passengers somewhere on the river downstream of the Margaret Bridge as far as the southern state border.

[34] On 31 May the Ministry of Interior announced that attempts to lift and recover Hableány during the first two days had been unsuccessful and that it was seeking new ways to search the lower deck for trapped passengers.

[35] As of 6 June 2019, divers were attaching a harness so the sunken boat might be recovered by a 200-ton lift capacity floating crane, the Clark Ádám; water levels at that time were too high to begin the salvage operation.

[54] In March 2020, prosecutors charged Chaplinsky for "reckless misconduct in waterborne traffic leading to mass casualties" and "35 counts of failure to provide assistance" after the collision.

[55][56] During trial, prosecutors accused him for "distracted for personal reasons" during the crucial first five minutes after his ship left its mooring and "did not radio or send out emergency sound signals".

[53] In September 2023, Chaplinsky was sentenced to five years in prison after being found guilty of gross negligence, though he was acquitted on the charge of failure to provide help.