WASHINGTON (Reuters) – Federal agencies are investigating the crash of a helicopter with three passengers into the Atlantic Ocean close to swimmers and sun bathers in Miami Beach, Florida, on Saturday. A Robinson R44 helicopter plunged into the ocean close to a crowded beach at 1:20 p.m. local time, the Federal Aviation Administration said. The agency is investigating the cause of the crash with the National Transportation Safety Board. The Miami Beach police and fire departments responded to the scene and said on Twitter that two of the passengers were transported to a local hospital “in stab…