titan (submersible)
An experimental tourism submersible built by OceanGate, designed to take rich customers to the wreckage of the Titanic. It used a cylindrical design with a carbon fiber body, had a capacity of five people, even an onboard lavatory, and was controlled by a Logitech F710 gaming controller. Its design was heavily criticized by submarine experts and was largely made of off-the-shelf components (such as using construction pipes for ballast).
On June 18, 2023, 740 kilometers off the coast of Newfoundland, Canada, its surface ship lost contact with the Titan 1 hour & 45 minutes into the dive, but didn't call for help until 8 hours later, after the sub was supposed to return. Multiple government agencies from the United States and Canada were involved in the massive search spanning four days and over 25000 square kilometers. By June 22, the date when the emergency oxygen was predicted to be depleted, an ROV had located debris which was confirmed to be part of the sub, and later had been determined that the vessel had imploded. All 5 people onboard, including OceanGate's CEO have been declared dead. Subsequent investigations revealed the vessel was practically doomed from the start, due to poor design and ignorance by the company's CEO, including him firing an expert for telling him his vessel was not seaworthy and previously saying things that essentially amounted to "screw safety."