The search ended in heartbreak Thursday.

Today, investigators continue to scour the ocean floor for answers into how the “catastrophic implosion” claimed the lived of all five passengers on the submersible that lost contact with its mother ship over the weekend.

With international media all emerging on St. John’s in recent days, the search effort ended after debris from the Titan was found near the wreck of the Titanic. According to the U.S. Coast Guard, the debris field was consistent with the loss of the vessel’s pressure chamber.

Lost in the tragedy were Hamish Harding, a billionaire and explorer, Paul-Henry (PH) Nargeolet, a French explorer, Shahzada Dawood and his son Suleman, members of a prominent Pakistani family, and OceanGate CEO and Titan pilot Stockton Rush.

The devastating news came on day four of a race against the clock to find the Titan, which was expected to run out of oxygen early Thursday morning.

“We’re going to continue to investigate the site of the debris field,” U.S. Coast Guard Rear Admiral John Mauger said at Thursday’s press conference. “This is something that happened in a remote portion of the ocean with people from, you know, several different countries around the world, and so it is a complex case to work through.”

Although there’s relief that crew members lost their lives quickly during the implosion, the focus is shifting to why? Was it materials, the engineering of the design or human failure. All these questions will be answered through the investigation, officials say.

The submersible lost contact with its surface ship the Polar Prince early Sunday morning after leaving St. John’s. The missing vessel was heading to the 1912 wreckage of the Titanic, located about 600 kilometres off the coast of Newfoundland. The tours are owned and operated by OceanGate, who issued a statement immediately following Thursday’s news that the debris field had been found.

“This is an extremely sad time for our dedicated employees who are exhausted and grieving deeply over this loss. The entire OceanGate family is deeply grateful for the countless men and women from multiple organizations of the international community who expedited wide-ranging resources and have worked so very hard on this mission. We appreciate their commitment to finding these five explorers, and their days and nights of tireless work in support of our crew and their families,” read a statement from OceanGate.

According to CTV News, OceanGate Expeditions has been running tours and research trips to the Titanic since 2021. The company has carried at least 46 people to the wreck with some paying approximately $300,000 for the experience.