Five people were part of the crew of a submarine that descended into the Atlantic Ocean to observe the remains of the Titanic liner.

Two hours after submerging, communications were lost, triggering a multinational search and rescue operation between the United States and Canada. The tour operation was led by OceanGate Expeditions.

A submarine used by tourists to see the remains of the Titanic in the Atlantic Ocean disappears

The U.S. Coast Guard said in a statement Monday that one of its planes was “looking for five people after the Canadian research vessel Polar Prince lost contact with its submarine during a dive about 900 miles (1,450 kilometers) to the east.” from Cape Cod.”

The Canadian Coast Guard said it is also taking part in the search with a fixed-wing aircraft and ship being sent to the search area.

One of the crew members is British aviator Hamish Harding, who had left a message on social networks about the expedition. A day before departure, he announced that he will participate in the “RMS TITANIC mission as a mission specialist on the submarine descending to the Titanic.”

“Due to Newfoundland’s worst winter in 40 years, this mission is likely to be the first and only manned mission to Titanic in 2023,” the 58-year-old aviator added.

“A weather window has just opened and tomorrow we will try to dive,” he added.

It is not known who else was on board. Harding wrote that “the submarine team has a few legendary explorers, some of whom have made more than 30 dives on the RMS Titanic since the 1980s.”