21. A Thorough NASA Investigation
NASA launched a full investigation into the incidents behind the successful failure of the mission and found that the problem lay with the manner in which the oxygen tank had been manufactured. There were many exposed wires and somehow this crucial part had missed the pre-flight inspection by a crew of technicians.
It was those very wires that sparked the fire that eventually destroyed one oxygen tank and damaged the Odyssey. So, it was determined that the Apollo 13 mission failed due to the lethal combination of both manufacturing and testing mistakes.