UN Secretary-general Ban Ki- moon said Wednesday that more than a quarter of a million people were killed by disasters worldwide last year, making 2010 one of the deadliest years in more than a generation.

Addressing an informal thematic debate in the UN General Assembly on disaster risk reduction, the secretary-general warned that natural disasters could make 2011 as costly as 2010, saying " we have already seen grievous disasters in Australia and Brazil."

With earthquakes, heat waves, floods and snowstorms affecting 208 million people, killing more than 250,000, and costing 110 billion U.S. dollars in losses last year alone, the 192-member General Assembly on Wednesday debated on mitigation steps such as building safer schools, hospitals and cities to reduce the terrible toll.

In his speech at the open debate, Ban recited the litany of natural disasters of the past year -- earthquakes in Haiti, Chile and China, floods in Pakistan and Europe, wildfires in Russia and the United States, and cyclones and tropical storms in Asia.

"Barely a day went by without lives devastated, homes demolished, people displaced, and carefully cultivated hopes destroyed," he said. "It was one of the deadliest years in more than a generation."

"Children are among the most vulnerable," he said. "Thousands died last year as earthquake, flood or hurricane reduced their schools to rubble. These deaths could have been prevented. Lives can be saved by advance planning -- and by building schools, homes, hospitals, communities and cities to withstand hazards. Such measures to reduce risk will grow ever more important as our climate changes and extreme events become more frequent and intense."