 Another Defense Intelligence Agency document speculates that, because the "shock and pressure waves cause minimal damage to brain tissue... it is possible that victims of FAEs are not rendered unconscious by the blast, but instead suffer for several seconds or minutes while they suffocate".First attempts had previously been undertaken during the Second World War by the German Luftwaffe and Wehrmacht, their inventor being Mario Zippermayr.The initial weapon – named "Taifun" (Typhoon)—was based on coal dust and concentrated oxygen pumped into a space and detonated.