i always have my seatbelt fastened whenever i'm in my seat, you never know when you might run into some CAT or some autopilot malfunction as in this case.
it's just really bad luck for the people that got injured while they were likely waiting for the toilet. and a "serves you right" for passengers not having your seatbelts on when in your seat. it doesn't have to be tight, just as long as it holds you down in case the plane gets into an UA situation.
how many seatbelts do you hear unbuckling immediately after the pilot turns the fasten seatbelts signs off? lots!
lesson learnt...wear your seatbelt when seated!!!!
