next tonight here, a passenger plane plunging more than 20,000 feet in just minutes. oxygen masks dropping. passengers then told to brace for impact. here s adrienne bankert. fasten your seat belts! fasten your seat belts! reporter: terrifying moments, as an air asia jet plummets. oxygen masks drop as the cabin loses pressure. the next bit, one of the stewardesses was running down the aisle, screaming, put your belts on, put your belts on. reporter: it happened just a half hour into a flight from perth, australia, to bali. the crew making desevend descent, dropping 34,000 feet to 10,000 feet in minutes. passengers sharing those horrifying moments and videos with australia channel 9. many say they thought they were going to die. i picked up my phone and sent a text message to my family, just hoping they would get it. reporter: chris jeanes, who was reportedly planning to propose to his girlfriend in bali, instead grabbing an oxygen mask and proposing right there. those pas