Titanic tourist submarine 'may be stuck in ship's wreckage 12,500ft below Atlantic': Cold War sonar plane and second sub deployed in race against time hunt for vessel that has 60 hours of air left and has been missing for more than 24 hours | Daily Mail Online

https://www.dailymail.co.uk/news/article-12210873/Tourist-sub-taking-groups-Titanic-wreckage-goes-missing.html