Assertion: explosion | /r/HasProperty | described by crew member helmut lau
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text: The team, led by British aeronautical engineer Jem Stansfield and US airship historian Dan Grossman, concluded that the ignition took place above the hydrogen vent just forward of where Mark Heald saw St. Elmo's Fire, and that the ignited hydrogen was channelled down the vent where it created a more explosive detonation described by crew member Helmut Lau.