Before revision: Unplanned decompression upPassenger oxygen mask deployment Unplanned loss of cabin pressure at altitude/in space is rare but has resulted in a number of fatal accidents.
After revision: (Photo shows an accidental deployment, rather than a genuine deployment for an emergency)Unplanned decompression upPassenger oxygen mask deployment Unplanned loss of cabin pressure at altitude/in space is rare but has resulted in a number of fatal accidents.