titan submersible

Old footage from inside the Titan depicts the moment the incident occurred while approaching the Titanic
Excerpts from last year's documentary about the Titanic wreck expedition clearly show what happened to the submersible Titan.
Why is finding a missing submarine in the ocean like 'looking for a needle in a haystack'?
On June 19, OceanGate Expeditions announced that their submarine had suddenly disappeared at sea with 5 expedition members.