All passengers are believed to be lost after a desperate dayslong search for a submersible carrying five people vanished while on a tour of the Titanic wreckage off the coast of Newfoundland, Canada.

The 21-foot deep-sea vessel, operated by OceanGate Expeditions, lost contact about an hour and 45 minutes after submerging on Sunday morning with a 96-hour oxygen supply. That amount of breathable air was forecast to run out on Thursday morning, according to the United States Coast Guard, which is coordinating the multinational search and rescue efforts.