According to The Ponca City News, Officials say that a Kansas firefighter, along with three of his family members and family friend, were killed in the crash of a small aircraft that occurred in northern Oklahoma Saturday morning. The Independence Rural Fire Department says Sycamore, Kan. firefighter Nicholas Warner, two of his sons, his father Bill Warner and family friend Tim Valentine died when the aircraft they were traveling in crashed northwest of Ponca City at 10:45 a.m.. Officials say that the Kansas registered plane was leaving the Ponca City airport when it lost altitude and crashed. National Transportation Safety Board spokesman Peter Knudson said investigators, who have been there since Sunday, wrapped up the on-scene portion of their investigation on Monday.