What we know about missing tourist submarine that vanished on an expedition to Titanic shipwreck

A British billionaire explorer, a Pakistani father and son, a French diver and the CEO of a submarine tourist trip company are in a race against time for their lives as the 96-hour window to save them from a missing underwater sub is closing in.

On Sunday morning, when OceanGate Expedition’s sub left its mother ship around 900 miles east of Cape Cod, Massachusetts, the five passengers hoped for a trip of a lifetime getting up close and personal with the wreckage of the Titanic.

Follow the latest updates on the missing Titanic submarine here

But, in a chilling echo of the fate of the doomed White Star Line vessel, the adventure took a dramatic turn.

Just one hour and 45 minutes into the journey, the sub lost contact with life above the surface.

Now, more than two days on, the five-person pod is nowhere to be found.

In a press conference on Tuesday afternoon, US Coast Guard Captain Jamie Frederick assured that authorities are doing everything possible to locate the missing vessel as the search intensified with more technology.

Mr Frederick confirmed that the vessel has “40 to 41 hours” of oxygen supply left, meaning it is expected to run out by 5.30am ET (10.30am GMT) on Thursday.

He also acknowledged that officials do not know if crews will be able to rescue the sub even if they do manage to find it before the oxygen runs out.

In a dramatic turn, a Canadian aircraft searching for the missing sub detected intermittent banging noises from the vicinity where the divers were last located. The crew heard banging sounds every 30 minutes on Tuesday and again four hours later, after additional sonar devices were deployed.

Here’s what we know so far:

What happened?

On Sunday morning (18 June), the Titan sub, owned by OceanGate Expeditions, set off on its excursion to the Titanic’s underwater grave with the research vessel the Polar Prince.

The expedition began with a 400-nautical-mile journey out into the Atlantic Ocean, about 900 miles off the coast of Cape Cod, Massachusetts.

The submersible was then released from its mother ship and began its descent 13,000 feet below the water’s surface to the wreckage.

The vessel is supposed to transmit a signal back to the Polar Prince every 15 minutes but it lost contact after one hour and 45 minutes.

What…