Missing Titanic submersible: Timeline of events

Rescuers were scouring thousands of square miles in the remote North Atlantic for a third day on Wednesday, racing against time to find a missing submersible after it disappeared while taking wealthy tourists to see the wreckage of the Titanic in deep waters off Canada's coast.

The 21-foot Titan has the capacity to stay underwater for 96 hours, according to its specifications - giving the five people aboard until Thursday morning before air runs out. One pilot and four passengers were inside the submersible early on Sunday when it lost communication with a ship on the surface about an hour and 45 minutes into its dive.

Start of the voyage

Operated by US-based OceanGate Expeditions. the submersible begins its dive to the wreck of Titanic on Sunday morning. OceanGate said that the team communicated with the crew on the surface every 15 minutes or less when needed.

Also read | Missing Titanic submersible: Why are undersea rescues so difficult?

Titan goes missing

The 21-foot-long pilot-driven submersible Titan lost contact with its parent surface vessel on Sunday morning about one hour, 45 minutes into what should have been a two-hour dive to the site of the world's most famous shipwreck. The mini-sub can remain underwater for 96 hours, giving its occupants until Thursday morning before their air tanks would run out, assuming that the Titan was still intact.

Rescue ops begin

US and Canadian ships and planes started search on Monday for the submarine. The private company that operates the submarine, OceanGate Expeditions, said in a statement on Monday that it was "mobilizing all options" to rescue those on board.

France joins rescue mission

France will send a ship equipped with a deep-sea diving vessel to the rescue operation following the disappearance of a submersible which took wealthy tourists to visit the site of the Titanic wreckage, the French education ministry said on Tuesday.

Underwater sounds detected

Search teams detected underwater sounds while scanning the North Atlantic for the tourist submersible, the US Coast Guard said early on Wednesday. The detection of the sounds by Canadian aircraft was reported by the Coast Guard as the clock ticked down to the last 24 hours of the craft's presumed oxygen supply. Robotic undersea search operations were diverted to the area but there was still no tangible sign of the missing vessel, the Coast Guard said on Twitter.

(With Reuters inputs)