Flight attendant urges passengers 'watch safety demo' after Southwest Airlines horror reveals 'big mistake'

A former flight attendant has urged travellers to watch safety demos after the Southwest Airlines horror revealed passengers making a 'big mistake' with their oxygen masks.

Bobby Laurie, an ex-American flight attendant and travel expert, shared a photo online of panicking Southwest passengers wearing their masks over their mouths... but not their noses.

He wrote: "People: Listen to your flight attendants! Almost everyone in this photo from [SouthwestAir] today is wearing their mask wrong.

"Put down the phone, stop with your selfies...and listen...Cover your nose [and] mouth."

One Twitter user questioned why it mattered so much, saying "they survived".

The former cabin crew member continued: "Sure they [survived], because the pilots managed to get the aircraft to a level in which the cabin was pressurised and they could breathe.

"Had they not been able to safely and quickly...there would have been a different outcome. Flight attendants are aviation's first responders - listen!

"It would have [mattered] a lot if they were at 35,000ft. They would be dead. Period."

The picture was taken by marketing entrepreneur Marty Martinez, 29, who was on board the Southwest flight when its engine exploding during a journey from New York to Dallas.

Mr Martinez paid $8 for WiFi to Facebook Live what he thought were his "final moments" during the terrifying mid-air emergency.

The terrifying ordeal claimed the life of mother-of-two Jennifer Riordan who was killed when she was almost sucked out of the window.

The pilot of the plane, which had 149 people aboard, took it into a rapid descent and made an emergency landing in Philadelphia.

Southwest Airlines, which is based in Dallas, said there were no problems with the plane or its engine when it was inspected on Sunday.