The crew of the missing Titan tourist sub have less than 24 hours of air left after going missing whilst trying to explore the wreckage of the Titanic.
It was first reported missing on Sunday, as the crew including British explorer Hamish Harding along with the founder of the diving company OceanGate Stockton Rush had not resurfaced.
French submersible pilot, Paul-Henry Nargeolet and Pakistani businessman Shahzada Dawood and his son, Suleman, were also travelling on the sub.
Earlier today it was reported that 'noises' had been heard by sonar crews taking part in the search, giving fresh hope that the passengers are still alive.
This is what we know so far and the timeline leading up to the sub being reported missing.
Saturday, June 17.
2pm: Billionaire explorer Hamish Harding posts on Instagram to reveal he is among the crew of a submersible vessel on their way to explore the Titanic wreckage.
He said: 'I am proud to finally announce that I joined OceanGate Expeditions for their RMS TITANIC Mission as a mission specialist on the sub going down to the Titanic.
'Due to the worst winter in Newfoundland in 40 years, this mission is likely to be the first and only manned mission to the Titanic in 2023. A weather window has just opened up and we are going to attempt a dive tomorrow.'
Sunday, June 18
4am: The crew including French diver Paul-Henri Nargeolet, Pakistani businessman Shahzada Dawood and his son Sulaiman Dawood begin their 4,000m descent to the wreck.
The Polar Prince icebreaker sailed around 900 miles off the coast of Newfoundland, where it set anchor.
7.30am: The crew was dropped into the ocean in their 22-foot long submersible vessel, the Titan.
9.47am: Just over two hours later the vessel lost contact with the Polar Prince.
The vessel was programmed to send out a 'ping' every 15 minutes to indicate its location.
10am: The final signal was sent and there has been no further contact with the vessel since.
11.15am: Last photo of the Titan shared by Hamish's company
5.15pm: The vessel was due to resurface around nine hours after starting the dive.
5.40pm: When the submersible failed to resurface, the crew raised the alarm with authorities.
10pm: All five members of crew were identified as being on board.
Monday, June 19
9am: Authorities revealed the Titan was missing and a large-scale search operation had been launched.
The US Coast Guard began a sweeping search of a 5,000sqm area about 900 miles off the coast of Cape Cod, Massachusetts. The Canadian Coast Guard said it too is taking part in the effort with fixed wing aircraft and a ship.
1.30pm: The US Coastguard's Northeast tweeted that a C-130 Hercules reconnaissance aircraft had been dispatched to search for the Titan.
P8 Poseidon aircraft with underwater sonar capabilities joined the search on Monday afternoon.
Tuesday, June 20
Submersible craft including an unmanned US Navy Curv-21, which can reach depth of 4,000m, also joined the search.
The Polar Prince and 106 Rescue Wing continued to conduct surface searches throughout Monday evening.
A Canadian Aircraft P3 Aurora joined the effort, as the search area expanded to 10,000sqm.
6pm: US Coast Guard Rear Admiral John Mauger told reporters it is a 'challenge' to conduct a search in such a remote area, but it was deploying all available assets.
Wednesday, June 21
6am: It is reported that 'noises' have been heard by sonar crews searching for the missing sub, giving fresh hope that passengers are still alive.
Thursday, June 22
8am: The Titan's oxygen supply is due to run out
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