There have been cases of a very small number of survivors in very serious accidents, but it is "very rare" for there to be only one, a professor told Newsweek.

The survival of a passenger who escaped through an exit door seconds after his Air India flight crashed killing everyone else on board has prompted speculation over whether his seat, 11A, is the safest.

It seemed impossible, but shortly after news broke that an Air India flight had crashed in the city of Ahmedabad, video started circulating on social media showing a man walking from the scene in a bloodstained shirt.