Doors are ‘armed’, to auto inflate when the doors are opened. You can watch the flight attendeants flip a large lever and/or attach a bar at the bottom of the doors to do this.
Force of impact/ flexing of fuselage probably activated the switch.
Worthy of an AD.
I personally muscled at least 2-300 of them on 747s, a300s, a310s,dc10s and 727s at Pan Am in 19 years I never ever saw 1 deploy inside the aircraft. Outside hell yes commissary did it many times as well as flight attendants not installing the safety pins and moving the lever to the disarm position we even painted the knobs red so they would see them
Force of impact/ flexing of fuselage probably activated the switch.
Worthy of an AD.
*********************************
YUP , from now on there’ll be a $50,000 bungee cord looped around the handle securing it ...