What we know about the missing OceanGate sub and its expedition
The eyes of the world are on an extraordinarily difficult rescue operation to find a missing submersible vessel carrying people to view the wreckage of the Titanic.
The five-person submersible had on board crew and paying tourists and was one of 18 "missions" planned by deep sea exploration company OceanGate Expeditions for 2023 and onwards.
According to its website, OceanGate successfully completed similar expeditions to the Titanic wreck - which lies 3800 metres below the surface around 685 kilometres south-southeast of the coast of Newfoundland - in 2021 and 2022.
The company said the aim of its missions was to document the Titanic and its rate of decay, by collecting images, videos, laser and sonar data.
The expeditions were being funded by tourists, with the in...