After six days of scouring the waters off Italy, which included the use of a robotic underwater camera, for missing American balloonists, authorities have called off their search (via CNN). It is difficult to presume anything except that Carol Rymer Davis of Denver and Richard Abruzzo of New Mexico died during their attempt to win the world's longest-running balloon competition, the Coupe Aeronautique Gordon Bennett, as they did in 2004 (via CBS News). The last time 47-year-old Abruzzo and 65-year-old Davis were in touch with anyone was three days after setting off from Bristol, England. The two were nearing Italy and contacted that country's coast guard by radio to say their balloon had suffered "a sudden and unexpected failure," and that their craft was plummeting toward the sea.