Acadia National Park rangers said a broken rope was to blame for a fall that injured three climbers on a 25-foot-high rock face and led to a complicated rescue. Ranger Will Overton said that two men tumbled from the rock face at Otter Cliffs and that one or both landed on a third climber at the bottom Sunday morning. A man and woman were taken away in an ambulance. It took roughly four hours to get them hoisted to safety in litters. The injuries were not believed to be life-threatening. Park officials declined to identify the victims.