Summary:
A cloud that sparked a major alert in Argentina has caused a major evacuation of the city of Buenos Aires.

Full article:
(CNN) -- A foul-smelling cloud wound its way through Argentina's capital Thursday, but it was not toxic as initially feared, officials said. Civil defense authorities in Buenos Aires advised residents to remain indoors with windows and doors shut as a cloud emanated from a container fire at the city's port. The smelly cloud and reports that the burning container had chemicals inside caused alarm throughout the capital. But it was quickly determined that the fumes were not dangerous. The container held sodium bicarbonate and posed little risk to the population, the country's security secretary, Sergio Berni, said. "We implemented the emergency plan; the situation is under control," he said. Nonetheless, the cloud was enough to disrupt the subway system in Argentina's largest city.