Assessing the floods' damage

(CNN) -- Following is a recap of the effects of flooding in some central European countries:

Prague faced some of the worst flooding in its history, prompting the removal of 400 animals from its zoo. A chemical plant near Prague started leaking Thursday, spewing potentially deadly chlorine gas into the air.

Officials estimate the costs of cleaning Prague could surpass $2 billion.

The flooding is being called the worst for a century in Austria, where thousands of people have been evacuated from the Salzburg and Upper Austria provinces. Johannes Guger, head of international relations for the Red Cross, told CNN that seven people had been killed in the floods. (Full Story)

Eight-thousand soldiers and firefighters were struggling to shore up weakening dams with sandbags, but the raging Danube has already broken through defences in the town of Ybbs in Lower Austria province.

More than 1,000 buildings in Salzburg are under water, Austrian radio reported.

P. Schadl, wrote an e-mail from Vienna to CNN, which said: "These are our darkest hours but together we are strong."

Dresden was evacuated late Thursday and early Friday as officials readied for an anticipated backwash wave originating from a dam break downstream on the River Elbe. The center of the city was abandoned.

Nine people have already died in the worst affected area of Saxony while about 20,000 people have been evacuated, including hospital patients.

In an e-mail to CNN, resident Peggy Steiniger recalled a mobile-phone conversation she had with a friend earlier Thursday: "I'm writing on behalf of my friend, who lives in a small town near Dresden, that got hit by the water really bad. '...It's the worst nightmare you can ever imagine!' she said this morning."

Russia has suffered twice this summer from severe flooding. Most of the victims in the latest downpours have been Russian tourists taking their holidays on the Black Sea.

Many of the 58 victims were swept away by swiftly moving water late last week.

Authorities fear the toll could rise. Thirty cars and buses remain on the sea floor, and authorities have been unable to search them so far.

The situation could be complicated by new storm warnings issued for the area. (Full Story)