the submersible they were is into the sea returned to port today. our ron allen was there. reporter: today the polar prince on a solemn journey, the support ship, flags at half mast, that launched the titan submersible on its fatal expedition, arriving back at home port. met by canadian investigators beginning to try to figure out what caused the disaster that killed the five men that left here aboard the ship. do you expect to be able to answer the question of what caused this implosion? we take the time we need to do a thorough investigation, and we re in the early stages. and we need to scope out the lines of inquiry. reporter: investigators say they ve interviewed crew, relatives of the victims aboardi ship, retrieved voice and data recorders. as maritime experts focus on the titan s carbonfiber hull and that its owner and pilot, stockton rush, killed in the implosion, apparently ignored warnings to have the vessel tested and certified by independent agencies. i d lik
surface. he was one of the five people killed. and now oceangate and its ceo are under intense scrutiny. officials are saying the vessel suffered a catastrophic explosion. gabe, what have you heard about any consequences or april into the company? experts say it is basically the wild west, diving in these international waters, there is little to no regulation. oceangate is now under the microscope. we know experts have been raising red flags for years about this vessel. warning it could end in to catastrophe. this morning stockton rush and his ill-fated titan submersible facing intense scrutiny. rush who perished in the tightend had a reputation as a visionary, but also a self proclaimed world breaker. i think it was macarthur who
microscope, and submersible experts have been raising flags about this submersible, and the way it was built, and how it was tested and all of this leading up to that it could end in catastrophe. reporter: this morning, former oceangate ceo stockton rush and the titan submersible facing scrutiny. rush had a reputation as visionary and self-proclaimed rule-breaker. i think it was general macarthur said that you are remembered for the rules that you i have broken the rules with good logic and engineering behind me. reporter: the scientist said that he would have gone on the expedition himself if he had the chance. there is always a chance of catastrophic implosion. it is something that we know about it. it is something that we plan for, and plan against. and it is just a known risk.
i think it was general macarthur said, you re remembered for the rules you break. and, you know, i ve broken some rules to make this. i think i have broken them with logic and good engineering behind me. the carbon fiber and titanium, there s a rule you don t do that, well, i did. reporter: but we re now learning more about concerns over using carbon fiber and titanium to make the experimental sub, an untested material at extreme depths over time. the titan made 13 trips down to the titanic over two years. this is not like being a passenger on the first couple of days of service of the new airbus a380, right? this is like being a test pilot on a plane that has never flown. reporter: explorer josh gates passed on a trip to the titanic on the sub two years ago, after several of its systems failed during a test dive. carbon fiber is a miraculous material. it s what we re using to build next generation airplanes out of the dreamliner, the a350, things like that. but it s not partic
shrink. we are very aware of the time sensitivity around this mission. reporter: experts still hoping the sounds are from those trapped onboard and the resources deployed can effect a rescue. it is encouraging there did seem to be a pattern to it. we ll continue to hold out hope. reporter: the vessel was headed to view the titanic wreck that sits nearly 13,000 feet deep but lost contact on sunday just 1:45 into its descent. five onboard including oceangate ceo and founder stockton rush. i d like to be remembered as an innovator. i think it was general macarthur said you re remembered for the rules you break. you know, i ve broken some rules to make this. i think i ve broken them with logic and good engineering behind me. reporter: now questions surrounding the safety of the vessel, which was not inspected and classed by an independent group that sets safety