The helicopter was destroyed when it crashed into Choctawhatchee Bay at about 0043 Central time; the Commercial-rated pilot, paramedic and flight nurse aboard the air ambulance flight were fatally injured. Instrument conditions prevailed; no flight plan had been filed. Earlier, at 0041, the accident pilot called his dispatcher via radio and reported airborne with three persons on board, 2 hours 20 minutes of fuel and an estimated flight time of 10 minutes. At 0043, the helicopter called via radio and reported that they were returning to base due to weather. The dispatcher did not talk with the flight after this. At 0050, the dispatcher cleared the Airheart One call, believing that they were back at base due to the short flight time. At 0610, the relief pilot that was coming on duty advised that the helicopter was not at its base. Search and rescue operations were initiated and the wreckage of the helicopter was located in Choctawhatchee Bay about 0820. A witness, who was fishing nearby between 0030 and 0100, reported observing an unknown aircraft flying to the north. The aircraft made a turn toward the east and descended. He did not see or hear the aircraft after this. Recorded radar data showed that the flight climbed to 900 feet while proceeding north across the bay. The flight then descended to between 700 and 800 feet and initiated a turn to the east. At 0042:49, the last radar contact was recorded when the flight was at 700 feet, flying on a east-southeast heading.