From a story on politico.com by Eric Bazail-Eimil headlined “Missing Titanic tourist sub experienced ‘catastrophic’ implosion, Coast Guard says”:

Experts have assessed that the debris field found on the ocean floor near the Titanic shipwreck came from the body of a missing tourist submersible that disappeared Sunday, Coast Guard officials confirmed on Thursday. All five people aboard are now believed dead.

“The debris is consistent with the catastrophic loss of the pressure chamber,” Rear Adm. John Mauger, the head of the search-and-rescue operation, said at a news conference on Thursday afternoon in Boston. “On behalf of the United States Coast Guard and the entire unified command, I offer my deepest condolences to the families.”