Do not, 'under any circumstances', open that door. = 'Under no circumstances' are you to open that door. [=no matter what happens, do not open that door]
Due to 'circumstances beyond our control' [=things that have happened that we cannot change or influence], the flight is canceled.
She says that her client is 'a victim of circumstance' and should not be blamed for the accident.
(..) (SHOUTING) My orders? Shall we break off the attack? Regather our forces? Break off the attack? We have already sustained considerable losses. Perhaps, in the circumstance, it would be better if we took ourselves... (SCREAMS) (GRUNTS) All of my life, and all of your lives, have come to this point. (..)2016 TvShow: Vikings Title: The Last Ship Season: 4 Episode 10