by Li ZhouBuzzFeedHuffPost Reporter Nancy Guthrie, the 84-year-old mother of longtime Today show host Savannah Guthrie, was reported missing from her home near Tucson, Ariz., on Sunday. Since then, the local sheriff's department and federal agents have launched a comprehensive investigation into her disappearance, and family members have pleaded for her safe return. Don Arnold / WireImage As of Thursday, Pima County Sheriff Chris Nanos said he believed that Nancy was "still out there," though authorities have not received evidence that provided proof of life.