With the fragments of a huge comet on a collision course with Earth and threatening to wipe out most of humanity, an Atlanta-based structural engineer (Gerard Butler), his estranged wife (Morena Baccarin) and their young son (Roger Dale Floyd) are among those selected by the federal government for evacuation to a network of underground bunkers on the island of the title. But their exodus is hampered by the swift breakdown of the social order and by other factors, leaving them to fend for themselves. The highs and lows of human nature are revealed by the crisis and screenwriter Chris Sparling keeps the proceedings grounded both in the ordeals through which the trio passes and in the spouses’ effort to reconcile. Implicitly pro-life, director Ric Roman Waugh’s engaging action drama also showcases positive values via the courageous concern Butler’s character displays toward those in peril. But the mayhem the celestial fireballs unleash is too unsettling for kids while the vocabulary of the endangered will lead most parents to conclude that this quest for survival is not a journey for teens either. Mostly stylized but disturbing violence with occasional gore, a few gruesome sights, an adultery theme, brief scatological humor, several instances each of profanity and of milder swearing, about a dozen crude terms. The Catholic News Service classification is A-III — adults. The Motion Picture Association rating is PG-13 — parents strongly cautioned. Some material may be inappropriate for children under 13.