News came out earlier this morning that the submarine operated by Oceangate has lost contact with the surface team. It was attempting to dive down to the wreck of the Titanic.
This company operates charter trips to dive the Titanic site for about $250,000 USD per person.
It's a carbon fibre submersible able to dive as deep as 4000 meters. For reference Titanic lies at 3800 meters. It can carry 5 people in total.
Boston Coast Guard is operating the search, and there appear to be 3 ships heading to the site from St. John's to assist.
https://www.bbc.com/news/live/world-us-canada-65953941
Edit: Information also being posted on the Facebook "Titanic Book Club" page:
https://www.facebook.com/TitanicBookClub