3.1 Theories/Models and Use of Loss Causation Techniques (사고발생이론의 이해) - 2 ◈ Multi-Causal Theories (다중원인 이론) There may be more than one cause of an accident, not only in sequence, but occurring at the same time. For example, a methane explosion requires: Methane in the explosive range of 5% to 15% Oxygen, or air. Ignition source. The ignition will only happen if these three events occur together...