Eleven people were killed when a barge and a crowded catamaran collided in Russia's Volga River, pitching people off the sailboat and into the water.
Emergency Situations Ministry officials said rescue operations ended on June 12 when searchers found the body of the 11th victim, a woman.
The officials said five people were rescued after the collision late on June 11 near the city of Volgograd, of whom three were hospitalized.
Investigators said that according to the preliminary investigation, the owner of the catamaran, who was also at the helm during the incident, was to blame.
The owner "completely neglected both light and sound warning signals from the barge" and was "under the influence of alcohol," the Investigative Committee said in a statement, citing preliminary information from forensic experts.
The investigation also determined that 16 people were aboard the catamaran while its maximum capacity was 12, and the sailboat was not registered.
State-run news agency TASS earlier quoted the Russian Federal Agency for Maritime and River Transport as saying the catamaran did not have the required documents and identification lights.