Banging noise from doomed Titanic sub every 30 minutes led to survivor mystery dailystar.co.uk - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from dailystar.co.uk Daily Mail and Mail on Sunday newspapers.
Experts have revealed for the first time the theories surrounding the notorious banging noises heard by rescuers hunting for the doomed Titan submersible.
Played for the first time in a new documentary, the sound has a regular, steady beat which caught the attention of experts - and sparked hopes that they could be SOS signals from those on board.