Twisted pieces of the doomed 22-foot submersible Titan were unloaded from the Horizon Arctic ship at a Canadian Coast Guard pier in St. John’s, Newfoundland, on Wednesday. They were covered in white tarps before cranes lifted them onto trucks taking them to an official investigation site. Among the wreckage: the titanium end cap that held the sub’s 21-inch wide porthole; the porthole was missing. All five people on board the sub died in what the U.S. Coast Guard said was “a catastrophic implosion” just one hour and 47 minutes after the Titan deployed from the Canadian expedition ship Polar Prince…