A search and rescue operation is underway for a submersible touring the wreckage of the Titanic

The US Coast Guard launched a search and rescue operation for a submersible with five people on board that went missing during an expedition to the wreckage of the Titanic in the North Atlantic Ocean.

The military branch received a phone call Sunday informing them the Canadian research ship Polar Prince had lost contact with the underwater vessel and were overdue on checking with their communications, according to Coast Guard spokesperson Lt. Samantha Corcoran.

“Right now, we are just trying to use all efforts and work with international partners to try to get any resources out there to safely locate all five individuals,” she said.

The missing submersible lost contact 1 hour and 45 minutes into its descent, the Coast Guard said.