A male polar bear died after swallowing a toy ball thrown into his enclosure by a young visitor in a Russian zoo. According to zoo authorities, the 25-year-old polar bear, named Umka, suddenly collapsed on the ground while having breakfast in his enclosure in Yekaterinburg on Monday morning. Seeing him collapse, his carer immediately called for help following which a crew of vets arrived at the scene within ten minutes, but Umka had already died by then, Dailu Mail reported. After an autopsy was performed, it was found that his death was caused by a small rubber ball found in his stomach by the medical staff. Devastated by his sudden death, zoo staff claim that the rubber ball was likely thrown to Umka by a visitor.