TRENTON, Mo. (AP) — Authorities say a St. Louis-area psychiatrist and his son were killed when their plane crashed earlier this week in northern Missouri. The crash killed 82-year-old Philip Joseph LeFevre III, of Glendale, and 47-year-old Philip Joseph LeFevre IV, of Sunset Hills. The younger LeFevre was the president and CEO of Lending Partners. Their single-engine Cessna went down Monday in Grundy County but the wreckage was not found until Tuesday.. Authorities have not determined what caused the crash. Sheriff Rodney Herring said the aircraft was traveling from Moberly to Kirksville, but it went far off-track before the crash. The two men’s bodies were found in the plane.