NTSB releases preliminary crash report on Guthrie Co. plane crash
The report details the flight path of the private plane that was carrying 4 people to a hunting trip in Osceola, Iowa and the preliminary conclusion investigators have reached regarding the cause of the crash.
It notes that investigators found a large crack in one of the plane's muffler's, which was covered in "sooty deposits."
Those deposits were also found in a hose carrying hot air from the engine to heat the cabin.
The report also says autopsies showed the four victims had elevated levels of carbon monoxide in their blood.
We're also learning for the first time that the student pilot who took over the controls, 36-year-old Patrick Kellen of Le Mars, was a co-owner of the plan and had flown the plane alone several times since purchasing it in July.