Southwest Airlines: Picture of passengers during emergency landing shows why you should always watch the safety video

An image of the incident shows passengers have put their oxygen masks on incorrectly

The recent Southwest Airlines tragedy that claimed the life of a woman who was sucked through an aircraft window also showed up a worrying lack of knowledge about basic safety procedures.

An image shared online by Marty Martinez, a passenger on board flight 1380 from New York to Dallas, shows him and his fellow passengers wearing oxygen masks, which dropped down after one of the jet’s engines blew.

Oxygen masks should be placed over the nose and mouth (Facebook/Marty Martinez ) (Facebook/Marty Martinez)

However, as travel expert and former flight attendant Bobby Laurie pointed out on social media, none of the people in the picture are wearing their masks correctly.

He tweeted: “PEOPLE: Listen to your flight attendants! ALMOST EVERYONE in this photo from @SouthwestAir #SWA1380 today is wearing their mask WRONG. Put down the phone, stop with the selfies and LISTEN. **Cover your NOSE AND MOUTH.”

In the photo, the three passengers clearly shown only have the mask over their mouths, contrary to the advice given in the safety briefing at the start of every flight.

Some Twitter users responded that it didn’t really matter because everyone else had survived.

“It would have mattered a lot if they were at 35,000 feet,” replied Laurie. “They would be dead. Period.”

Wearing an oxygen mask is crucial in situations where there is a dramatic drop in cabin pressure, as passengers and crew can otherwise suffer from hypoxia, a deficiency in the amount of oxygen reaching the brain and other tissues. It can cause dizziness and disorientation, impaired judgement, unconsciousness and death.

Breathing solely through the mouth isn’t as efficient as breathing in through the nose, and can contribute to hyperventilation, particularly in a stressful situation.

“If it’s only covering their mouth, then they need to only breathe out of their mouth exclusively to receive enough oxygen to live until the aircraft has reached a low altitude to breathe,” wrote Laurie. “Cover both, removes the need to remind yourself to breathe from your mouth for starters.”