Investigators are continuing to scour the ocean floor for any insight into how a "catastrophic implosion" killed all five passengers of a Titanic-bound submersible that suddenly lost communication with its mother ship over the weekend, officials said. A dayslong international search effort concluded Thursday after debris from the submersible – known as the Titan – was found about 1,600 feet from the historic wreckage of the Titanic. Military experts found the debris was consistent with the disastrous loss of the vessel's pressure chamber, US Coast Guard Rear Adm. John Mauger announced. The passengers killed were a Pakistani businessman and his son, Shahzada and Suleman Dawood; British businessman Hamish Harding; French diver Paul-Henri Nargeolet; and Stockton Rush, the CEO of the vessel's operator, OceanGate Expeditions. As officials work to determine the timeline and circumstances of the accident, remotely operated vehicles will be used to map out the vessel's debris field, which is more than 2 miles deep in the North Atlantic Ocean, Mauger said. Officials have yet to conclusively determine whether the devastating implosion occurred at the moment when the submersible stopped communicating about 1 hour and 45 minutes into its dive, Mauger said. A senior Navy official, however, told CNN that a Navy review of acoustics data detected an "anomaly consistent with an implosion or explosion" on Sunday in the general area where the Titan was diving when it went silent. The information was "immediately shared" with on-scene commanders leading the search effort and was used to narrow the search area, the official said. The sound was determined to be "not definitive" and "the decision was made to continue our mission as a search and rescue and make every effort to save the lives on board." Once the search began, crews had sonar buoys in the water "nearly continuously" and did not detect any "catastrophic events," Mauger said. When asked whether any crew members' remains may be recovered, Mauger noted the "incredibly unforgiving environment" but said, "I don't have an answer for prospects at this time." One medical expert, however, told CNN's Anderson Cooper that a deep-sea implosion would leave no recoverable remains behind. "There would be virtually nothing," explained Dr. Aileen Marty, a disaster medicine expert at Florida International University. "They're very unlikely to find anything there of human tissue." The expedition was touted as a "truly extraordinary" once-in-a-lifetime experience and is part of the growing industry of adventure tourism for the ultra-wealthy. A seat on the expedition cost each passenger $250,000, an archived version of OceanGate's website shows. But the tragedy has brought renewed scrutiny of OceanGate's operations and the development of the 23,000-pound Titan craft amid mounting reports of safety concerns, mechanical problems and an alleged disregard for regulatory processes. OceanGate co-founder Guillermo Sohnlein on Thursday said the crew members' deaths are a "tragic loss for the families and for the ocean exploration community in general" and noted the inherent risk in such expeditions. "Those of us in the community that work at that depth know that that's always a risk," Sohnlein told CNN. "There's pressure down so intense that if there is a failure, it is an instant, catastrophic failure." — CNN
