"The Navy began listening for the Titan almost as soon as the sub lost communications, according to a U.S. defense official. Shortly after the submersible’s disappearance Sunday, the U.S. system detected what it suspected was the sound of an implosion near the debris site discovered Thursday and reported its findings to the Coast Guard commander on site, U.S. defense officials said. [...] The Navy said it shared its findings Sunday with the Coast Guard, which led the search, U.S. defense officials said. " https://www.wsj.com/articles/u-s-navy-detected-titan-sub-imp...