Yellowstone National Park is famous for its pure wildlife. Every year hikers go there to experience that. For the first time in the last 25 years, a human being gets attacked and killed by any bear there. According to the ABC News, a couple was hiking until they encountered a mother grizzly with cubs. The wife claimed they did nothing to excite the bears, but eventually got mauled by the mother which left the husband dead. The incident is a shocker in itself even though the park authority is not willing to capture or kill the bear since they believe it was the mother’s instinct that made the protective bear attack.