(CNN) -- Authorities in Italy have called off the search for two Americans who went missing during a hot-air balloon race. The search ended Monday afternoon and will not resume, said Massimo Maccheroni of the Italian coastal guards. No balloon debris was found during more than four days of searching, he said. A balloon carrying Richard Abruzzo of New Mexico and Carol Rymer-Davis of Colorado over the Adriatic Sea near Italy made a rapid descent during rough weather, conditions that would make their survival "unlikely," race organizers have said. "This is very pessimistic information," said a statement from the race...