From YahooNews: 

How not to open a grenade…

RIO DE JANEIRO, Brazil (Reuters) - A Brazilian man died Tuesday when he tried to open what police believe was a rocket-propelled grenade with a sledgehammer in a mechanical workshop on the outskirts of Rio de Janeiro.

Another man who was in the workshop at the time of the explosion was rushed to a hospital with severe burns, a police officer told Reuters. The workshop was destroyed and several cars parked outside caught fire.

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