View of the Argentinian small tanker Polaris, at anchor on the Paraguay River 45 km south of Asuncion on August 16, 2011. The Polaris, with a load of petrol, caught fire after colliding with a Paraguayan tug towing 16 barges Friday, but the firefighters could only extiguish the flames Monday, and four crew men, two Argentinians and two Paraguayans are still reported missing. AFP PHOTO/Norberto DUARTE (Photo credit should read NORBERTO DUARTE/AFP/Getty Images)