'It's Get to the Surface or Die'

As the search continues off the coast of Newfoundland for the Titanic-bound submersible that went missing over the weekend, more details have emerged about the five passengers on board. Action Aviation CEO Hamish Harding, a billionaire and British adventurer, is one of the five, as are French explorer Paul-Henri Nargeolet; Stockton Rush, the CEO of OceanGate Expeditions, the company that owns the Titan submersible; and Shahzada Dawood, one of Pakistan's richest men, and his 19-year-old son, Sulaiman, per WION. Shahzada Dawood, 48, the vice chairman of fertilizer firm Engro Corporation, lives with his wife in Surrey, England. In addition to Sulaiman, the couple also share a daughter, Alina. More on the missing sub:

• Lucky twist of fate: The Mirror reports on one man who was meant to have been one of the crew aboard—David Concannon, an attorney who's been diving since he was a teen. "I was supposed to be on this expedition and, indeed, on this dive, but I had to cancel to attend to another urgent client matter," Concannon wrote Monday on Facebook, noting that he'd since been recruited to assist in the rescue efforts.
• Previous close call: CBS News reporter David Pogue was on an OceanGate mission to the Titanic wreckage last summer (it's unclear if he was on the submersible itself or a support ship), and he tweeted Monday about his own experience when the submersible "got lost for a few hours" during its journey, per the Washington Post.
• Predictions: Pogue, who's written about his mission, tells the BBC things don't look great at the moment. "Really concerning," he says of the fact that none of the seven backup functions that would allow the submersible to resurface have yet worked. He notes that the passengers are sealed into the vessel from the outside, and that a crew would have to remove the bolts to let them out. As for what happens if the sub springs a leak or otherwise becomes trapped: "There's no backup, there's no escape pod. It's get to the surface or die."

• "Not optimistic": That's the take of former Simpsons showrunner Mike Reiss, who did the dive himself last year. "I know how vast the ocean is and how very tiny this craft is," says Reiss, who adds his dive also lost communications. "If it's down at the bottom, I don't know how anyone is going to be able to access it, much less bring it back up."
• What it's like on board: Historian and author Charles Haas of New Jersey journeyed on a small submarine to see the Titanic three decades ago, and he describes the trip as an uncomfortable one—passengers crammed into the tiny vessel had to wear six layers of clothing due to the water's near-freezing temps, as water vapor from their breath condensed on the ceiling and dripped back onto them. "It's not an environment where human beings are welcomed," he tells USA Today.
• "Race against time": Concannon tells the AP that the Titan submersible had 96 hours of oxygen when it set out on its mission early Sunday—meaning rescuers need to find and rescue its occupants by early Thursday at the latest. "It is a remote area—and it is a challenge to conduct a search in that remote area," says Rear Adm. John Mauger, a commander for the US Coast Guard, which also is searching for the vessel. "But we are deploying all available assets to make sure we can locate the craft and rescue the people on board."

(More Titanic stories.)