The sub lost contact more than an hour after beginning its descent towards the Titanic wreckage.
The leader of the team that found the remains of the missing Titan submersible broke down while discussing the rescue mission. Ed Cassano, the CEO of Pelagic Research Services, said at a press conference said his team was processing "a lot of emotions", according to Sky News. Titan lost contact with the ship on the ocean surface after it began its dive towards the Titanic wreckage on June 18 (Sunday). All five people were declared dead on June 22 (Thursday) after the vessel suffered a "catastrophic implosion", according to the US Coast Guard.
Those on board included British explorer Hamish Harding, Pakistan billionaire Shahzada Dawood and his son Suleman, CEO of the sub owner OceanGate, Stockton Rush, and French deep sea explorer Paul-Henri Nargeolet.
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Mr Cassano said his team was contacted soon after Titan lost contact 1 hour 45 minutes since its descent began. He said by the time Pelagic's deep-water remotely operated vehicle (ROV) Odysseus 6K arrived at the site of the Titanic, hopes of a rescue did not last long.
"Shortly after arriving on the seafloor, we discovered the debris of the Titan submersible...by 12 o'clock, a rescue turned into a recovery," Mr Cassano said at the press conference.
He then choked up and apologised to the mediapersons, saying members of his team were processing a lot of emotions. Me Cassano also asked everyone to recognise the "seriousness of the event" and to "respect the range of emotions" felt by those involved.
"Our plan of rescue was to - immediately upon finding Titan - latch onto her as quickly as possible and begin recovery," the rescuer said, adding that the scale of the challenge was "wild".
The vessel is believed to have imploded shortly after its descent, and its debris were located about 12,500 feet underwater.
The US Coast Guard later recovered the presumed human remains from the debris of the crash when it was brought ashore.