Flash flooding from a storm in Argentina has killed at least 50 people as emergency workers Thursday tried to save those stranded in Buenos Aires and La Plata. “We’ve never seen anything like it,” said Daniel Scioli, a provincial governor. “People were taken by surprise, and some didn’t have time to escape this deadly trap.” The government has declared three days of mourning, calling the flooding “an unprecedented catastrophe.” Most of the victims had been elderly people who drowned in the homes, although only half the bodies have been identified. More than 3,000 were evacuated, and 80,000 still do not have electricity. An estimated 16 inches of rain was dumped on La Plata on Tuesday night.