At least two people were killed and 100 injured when a sudden storm hit Hungary's capital, Budapest, as tens of thousands watched a firework display.
The two people killed were hit by a falling tree, officials said.
Hundreds panicked when the rainstorm broke and several people had to be rescued after being thrown overboard when two ships collided on the Danube.
People had gathered on the banks of the river to watch a fireworks display to mark Hungary's national day.
Families separated
Torrential rain and winds of up to 100km/h (62mph) tore down trees, smashed cars and windows and ripped tiles off rooftops.
"Two people died between Margaret Bridge and the Chain Bridge as a tree fell on them," an emergency official said.
I was scared to death because of the huge winds and I also feared that I would be trampled on by the crowd. People were screaming everywhere
Nora Kvasz
Of those also injured by the falling tree, two were taken to hospital with life-threatening injuries and two suffered serious injuries, Budapest Fire Brigade spokesman Peter Molnar said on state television.
Tens of thousands of people were watching the fireworks and a preceding air show from both sides of the Danube, which divides the capital into Buda and Pest.
Water surged through the city streets close to the river, including the area near the parliament which is on the river's banks.
"I was scared to death because of the huge winds and I also feared that I would be trampled on by the crowd. People were screaming everywhere," Nora Kvasz, who was in front of the parliament building, told AFP news agency.
Witnesses spoke of panic on the bridges spanning the river.
"We were in water up to the knees," Reuters correspondent Sandor Peto, who had been standing on the Elisabeth Bridge when the storm hit, said.
Police said they are trying to reunite many children and parents who were separated in the mayhem.