The boss of the Titanic submarine search has admitted rescuers hoped to "grab" the vessel and bring it to the surface before discovering it had imploded.
The chief executive of the Pelagic Research Services, Ed Cassano, whose team carried out the search for the Titan underwater vessel, revealed the plan to locate the submersible sitting on the sea floor with the five men all safe inside.
His team had envisaged four possible scenarios, with the best being that the Titan was resting on the seafloor but had lost the power to come back up.
Rescuers hoped to "grab the Titan" and lift the vessel up to the surface in this scenario.
Mr Cassano said: "The sub was not being tracked. We didn't know where it was....it's essential for safe operations.
"The plan was to grab the Titan, and once we'd grabbed the Titan, manipulate it. Then we had her.
"Then it was going to be attaching beacons...so if we lost her, other assets could track her. At that point we would begin recovery."
The ROV Odysseus 6K made its way to the site of the Titanic at 5am on June 22 after the vessel lost contact with the mothership 45 minutes into the deep-ocean dive.
Stockton Rush, 61, OceanGate's founder, Paul-Henri Nargeolet, 77, Shahzada Dawood, 48; his 19-year-old son Suleman; and Hamish Harding, 58, a billionaire explorer were all in the Titan when the vessel went missing.
He revealed the company's ROV had planned to attach beacons to the sub so other vehicles could track it if it became lost again.
“Once we came through 3,000m, these other vehicles could join us", he said.
The robot was the only vessel in the search capable of diving all the way to the Titanic wreckage to try and find the craft which had five passengers on board.
However, within minutes of reaching the Atlantic’s ocean bed after an hour and a half descent from the surface, the ROV quickly found mangled debris.
“It turned the operation from a rescue to a recovery mission,” he said.
Last week, officials discovered five fragments of the sub, including the vessel's tail cone and two sections of the pressure hell, which had been discovered less than 500m from the bow of the Titanic wreckage.
"Presumed human remains" were also recovered from the submersible's wreckage with US medical officials set to conduct formal analysis of the remains.
They were discovered when debris from the craft was recovered from the ocean floor on Wednesday.
Mr Cassano said he was "proud of the performance of our system" but was "very saddened we couldn't recover a viable sub".
Royal Canadian Mounted Police (RCMP) said they are looking into the tragic deaths.
