On Thursday, it was announced that all people on board the Titan submarine had lost their lives as a result of an explosion. Five men died on the tourist expedition to the wreck of the Titanic.

"I know there are many questions about how, why and when the explosion happened. Those are questions we're going to gather as much information as we can right now,” said John Mauger, administrator of the US Coast Guard.

He added that it was a "complex case" that took place in a remote part of the ocean and involved people from several different countries.

On Thursday, after days of aerial and underwater searches, a robotic submersible deployed by a Canadian ship discovered a submarine debris field 488 meters from the wreckage of the Titanic.

The victims are Stockton Rush, the executive director and founder of OceanGate, the creator of Titan and the company that carried out the expeditions, the well-known entrepreneur Shahzada Dawood, his son, Suleman, the British businessman and explorer, Hamish Harding, and the diver Paul-Henry Nargeolet.

Tributes for the victims and praise for the rescue teams spread across the world.

The tourist submarine made various expeditions to the wreck of the Titanic, which is located 3,800 meters below sea level, but something went wrong and it disappeared along with the tourists on board, without leaving a trace.

Nicolai Roterman, an ecologist and lecturer in marine biology at the University of Portsmouth, England, said the submarine's disappearance highlights the dangers and unknowns of deep-sea tourism.

"Even the most reliable technology can fail and therefore accidents will happen. With deep sea tourism on the rise, we should expect more incidents like this,” he said.

According to industry experts and former passengers, the Titan expedition was extremely dangerous due to the depth of the ocean.