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

The vessel lost contact 1 hour and 45 minutes into its dive Sunday, the US Coast Guard said. It has between 70 and 96 hours of life support, officials said.

Among those aboard are a British adventurer, a French diver and a Pakistani father and son, according to social media posts and a family statement.

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