Researchers discovered that as many as 600 million birds die in the US every year after flying into skyscrapers.
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Democratic Senator Bernie Sanders dropped out of the race for US president.
One of the world's most important medieval castles, Krak des Chevaliers, was conquered by Sultan Baibars.
The first idea of a fire escape was patented.
The first person in the world to be diagnosed with Alzheimer's died.
The Iron Lady Margaret Thatcher died at 87 years old.
