ROUGH CUT (NO REPORTER NARRATION)<br/> <br />STORY: A massive ice wall that is a key feature of Argentina's famed Perito Moreno glacier collapsed on Sunday after several large chunks broke off in recent days.<br/> <br />Located some 2800 kilometers southeast of Buenos Aires, the glacier is a major tourist attraction in the Argentine Patagonia.<br/> <br />The glacier, a massive tongue of ice in the Santa Cruz province that covers 97 square miles, advances yearly into a lake, known as Lago Argentino.<br/> <br />As Perito Moreno moves forward, it cuts off a river feeding the lake. Water builds up pressure and slowly undermines the ice, forming a tunnel until ice comes tumbling down.<br/> <br />The phenomenon repeats itself at irregular intervals, with the last major ice falls occurring in 2008.
