The pilot and four passengers aboard the ill-fated submersible that disappeared en route to the wreckage of the Titanic are believed to be dead, the US Coast Guard said on Thursday. The US Coast Guard said the submersible, missing for five days, imploded near the wreckage of the Titanic.

“Pilot and company chief executive Stockton Rush, along with passengers Shahzada Dawood and his son Suleman Dawood, Hamish Harding, and Paul-Henri Nargeolet have sadly been lost,” OceanGate Expeditions said in a statement.

Addressing the media, US Coast Guard Rear Admiral John Mauger said five major pieces of the Titan submersible were detected amid the debris around the Titanic site. He said the nose cone, located outside the pressure hull, was the first piece found.

The site of the fatal accident is believed to be 1600 feet (487 m) off the bow of the Titanic wreck, BBC reported.

“The debris field is consistent with a catastrophic implosion of the vessel,” Mauger said.

US Coast Guard Rear Admiral Mauger said he cannot confirm whether the US Coast Guard would be able to recover the bodies of the five passengers on board the Titan submersible. “This is an incredibly unforgiving environment,” he said.

Mauger said the remotely operated vehicles would remain on scene and continue to gather information. He said they would continue to investigate the site of the debris field.

“We have medical personnel on the scene, we have other technicians on scene, and we will begin to demobilise personnel and vessels from the scene over the course of the next 24 hours,” he further said.

The Titan was estimated to have oxygen supply of four days when it started its voyage on Sunday morning in the North Atlantic. The vessel began its two-hour descent to the wreck of the Titanic on Sunday morning. However, 1 hour and 45 minutes into its descent, it lost contact with the Polar Prince, the support ship that transported the craft to the location in the North Atlantic.

The search area was doubled in last-ditch efforts and authorities engaged in the rescue operations availed every available asset into the mission.