‘Titan’ sub’s oxygen is dwindling. How can passengers prolong survival?

Rescuers are racing against the clock to find a missing submersible that was set to tour the Titanic wreckage off the coast of Newfoundland.

The stakes are life and death for the five people on board OceanGate Expeditions’ underwater submersible Titan, which lost contact with its support ship shortly after it began its dive Sunday morning.

An estimated four days of oxygen supply is feared to run out Thursday morning around roughly 6 a.m. Eastern, raising concerns about the…