40 hours of breathable air left as search continues for missing Titanic tour sub

A massive search operation is underway to find a submersible with five people on board that went missing Sunday on a trip to view the wreckage of the Titanic.

Coast Guard officials estimate there is "about 40 hours of breathable air left."

Aboard are a British adventurer, a French diver, a Pakistani father and son and the founder of the company that operates the tour, according to social media posts, a family statement and sources.

The Titanic wreckage sits at the bottom of the ocean nearly 13,000 feet below the surface southeast of Newfoundland, Canada.

Source: CNN