Many of the photographs showed passengers wearing the drop-down masks, but only covering their mouths. The proper way to wear the masks is to cover both the nose and mouth.

Passengers wear oxygen masks as Boeing Dreamliner plunges 26,000 ft mid-air in Japan, weeks after Ahmedabad crash; know what went wrong ...

A doctor based in Dublin, Ireland, has debunked the idea that a face mask lowers oxygen levels. In fact, he's shown that even wearing several has no effect.

Dutch authorities said one victim of downed Malaysia Airlines Flight 17 was wearing an oxygen mask around his neck.