New information is released on a deadly plane crash that devastated Oklahoma State University more than a year ago.
This week federal investigators put out a report following the crash that killed four people, including two OSU coaches.
The crash killed OSU women's basketball coach Kurt Budke, assistant coach Miranda Serna and two longtime OSU boosters Olin and Paula Branstetter back in Nov. 2011.
The probable cause report said the 82-year-old pilot Olin Branstetter lost of control of the aircraft.
The NTSB though could not give any conclusive proof showing why the pilot lost control writing, "The reason for the pilot's loss of control could not be determined."
"You know, the report doesn't show pilot error; I wouldn't expect there to be," the pilot's son, Paul Branstetter, said. "Generically speaking, they call it a loss of control if any crash happened."
Paul Branstetter points out his dad had been a certified pilot and flight instructor.
Paula Branstetter had also been certified to fly but the NTSB report notes that Paula sat in a back seat after "the pilot decided that the male passenger (Budke) would ride in the right pilot seat."
The plane in question had been inspected just days before the crash.
The report details, "During the annual inspection, the mechanic noted that the muffler was inspected, removed, weld repaired and re-installed."
"We really will probably never know what happened in that situation," Paul Branstetter said. "The families, our family and the Serna's and the Budke's, will just hopefully be able to make peace with not ever knowing exactly what happened."
The flight left for Arkansas on a recruiting trip and was not paid for by OSU.
In the wake of the crash, university leaders amended their travel policies, placing greater restrictions on travel by coaches.