The Sikorsky S-43B flying boat was operating on an international service from Miami, FL to Rio de Janeiro, Brazil with en route stops at Antilla, Port-au-Prince, San Pedro de Macor¡s, San Juan, Port of Spain, Georgetown, Paramaribo, Cayenne, B‚lem, S?o Lu¡s, Fortaleza, Natal, Jo?o Pessoa, Recife, Macei¢, Aracaju, Salvador, Caravelas and Vit¢ria. The flight was circling Rio de Janeiro for a normal approach when the left engine lost power. The airplane yawed to the left and started a descending turn. The turn became sharper and the airplane descended at a steeper angle until it struck a caisson at Ilha das Cobras, in Guanabara Bay and crashed. PROBABLE CAUSE: “Loss of power from the left engine during landing approach necessitating an attempted landing under extremely hazardous conditions.”