Documents show the company whose submersible vanished in the North Atlantic on a tourist dive to the wreck of the Titanic was repeatedly warned that there might be “catastrophic” safety problems with the venture. With five people aboard an expanding array of ships and airplanes is searching for the Titan, operated by OceanGate Expeditions, the undersea exploration company based in Everett, Washington. David Lochridge, then OceanGate’s director of marine operations, said in a 2018 engineering report and lawsuit that the craft under development needed more testing and that passengers might be endangered when it reached “extreme depths.” The company disagreed, noting Lochridge wasn’t an engineer.