On Monday, Colo the gorilla was seen by visitors to Ohio's Columbus Zoo toting around a baseball cap—a favorite item of hers, the AP reports. On Tuesday, the oldest gorilla ever recorded died in her sleep, less than a month after her 60th birthday. According to CNN, Colo, the first gorilla born in human care, lived 20 years longer than an average gorilla. In a Facebook post, zoo CEO Tom Stalf says Colo "touched the hearts of generations of people." Colo had recently had a malignant tumor removed but was believed to be doing well. A cause of death is yet to be determined. The zoo plans to cremate her and bury her remains. Colo leaves behind three children, 16 grandchildren, 12 great-grandchildren, and three great-great-grandchildren. (More gorilla stories.)