In January and February of 2016, a total of 13 young sperm whales washed up on the beach near the town of Tönning in Schleswig-Holstein, Germany. An autopsy revealed that the whales had all died of heart failure. The researchers believe that the young bulls, all between 10-15 years old, may have entered the North Sea by mistake. Since the sea floor here is too shallow for these deep sea dwellers, it caused the whales to become disoriented and perish.