Parts of new film “The Impossible,” about the 2004 Indian Ocean tsunami, were impossible to watch for a viewer at the New York premiere. A guest at Calvin Klein’s screening Wednesday at the Museum of Arts & Design passed out during a dramatic moment. An onlooker explains the “really gross” scene involved actors coughing up “something” after they’ve been caught in the waves. “It was out of ‘Alien,’ ” our spy reports. “That’s when the commotion in the audience happened. Someone said the guy just couldn’t take it and blacked out.” Another source says, “He was having trouble breathing and everyone around him helped him out.” The film’s stars, Naomi Watts and Ewan McGregor, were there along with Petra Nemcova (who famously survived the tsunami hanging on to a palm tree), Liev Schreiber and Nora Zehetner.