Six people aboard a medical transport aircraft that went missing on Saturday while it was travelling from Bermuda to Boston are presumed dead, according to a statement from the flight's operator.On Sunday evening, the United States Coast Guard said it was ending its search for survivors off the coast of Nantucket, a Massachusetts island, reports BBC."We must now face the heartbreaking reality that the four members of our Latitude team, our patient and the patient's family escort, who were aboard...