A massive search and rescue operation is underway in the mid-Atlantic after a tourist submarine went missing during a dive to Titanic’s wreck on Sunday.
Contact with the small sub was lost an hour and 45 minutes into its dive, the US Coast Guard said.
Tour firm OceanGate said all options were being explored to rescue the five people onboard.
Tickets cost $250,000 (£195,000) for an eight-day trip including dives to the wreck at a depth of 3,800m (12,500ft)
Officials said, Government agencies, the US and Canadian navies and commercial deep-sea firms are helping the rescue operation.
Titanic’s wreck lies some 435 miles (700km) south of St John’s, Newfoundland, though the rescue mission is being run from Boston, Massachusetts.
The missing craft is believed to be OceanGate’s Titan submersible, a truck-sized sub that holds five people and usually dives with a four-day emergency supply of oxygen.
As of Monday afternoon, Rear Adm John Mauger of the US Coast Guard told a news conference: “We anticipate there is somewhere between 70 and the full 96 hours available at this point.”
He also said that two aircraft, a submarine and sonar buoys were involved in the search for the vessel but noted the area in which the search is taking place was “remote”, making operations difficult.
Rear Adm Mauger said the rescue teams were “taking this personally” and were doing everything they could to bring those on board home safely.
Hamish Harding, a 58-year-old British billionaire businessman and explorer, is among those on the missing submarine.
Over the weekend, Harding posted on social media that he was proud to finally announce that he would be aboard the mission to the wreck of the Titanic – but added that because of the “worst winter in Newfoundland in 40 years, this mission is likely to be the first and only manned mission to the Titanic in 2023”.
He later wrote: “A weather window has just opened up and we are going to attempt a dive tomorrow.”
OceanGate said its “entire focus [was] on the crewmembers in the submersible and their families”.
“We are deeply thankful for the extensive assistance we have received from several government agencies and deep sea companies in our efforts to re-establish contact with the submersible,” it added.
The company billed the eight-day trip on its carbon-fibre submersible as a “chance to step outside of everyday life and discover something truly extraordinary”.
The submersible usually carries a pilot, three paying guests, and what the company calls a “content expert”.
According to its website, two more have been planned for June 2024.