Officials in Russia said on Monday that least 55 people have died in the cruise boat sinking on the Volga River.
Eighty people have been rescued, but dozens remain missing.
The Bulgaria, a double-decked cruiser built in 1955, sank on Sunday with 208 people on board close to the city of Kazan.
It was licensed to carry only 120 people, although it is unclear if the overloading caused the accident.
The boat had been hit by bad weather.
President Dmitry Medvedev has ordered an investigation and declared Tuesday a day of mourning.
Relatives are waiting for news of their loved ones, although authorities say there is little chance of finding any more survivors.
As well as being overcrowded, the ship also had engine problems and listed to one side.
The Bulgaria’s sinking could prove to be the most deadly river accident in Russia for nearly three decades.
In 1983, a ship crashed into a railroad bridge on the Volga, killing at least 176 people.