https://www.bbc.co.uk/news/world-us-canada-65953872The submersible usually carries a pilot, three paying guests, and what the company calls a "content expert".
The trip sets sail from St John's in Newfoundland, which is around 370 miles (600km) from the wreckage site. Each full dive to the wreck, including the descent and ascent, reportedly takes around eight hours.
The OceanGate website lists three submersibles it owns, and only the Titan is capable of diving deep enough to reach the Titanic wreckage.
The vessel weighs 10,432 kg (23,000 lbs) and, according to the website, can reach depths of up to 4,000m and has 96 hours of life support available for a crew of five.
A vessel called the Polar Prince, which is used to transport submersibles to the wreckage site, was involved in the expedition, its owner told the BBC.
David Pogue, a CBS reporter who travelled in the Titan submersible last year, told the BBC about the issues that both the submersible crew and the land crew are likely to be experiencing, saying that there is currently "no way" to communicate with the vessel as neither GPS nor radio "work under water".
"When the support ship is directly over the sub, they can send short text messages back and forth. Clearly those are no longer getting a response," Mr Pogue said.
He added that because the passengers are sealed inside the vessel by bolts applied from the outside, "there's no way to escape, even if you rise to the surface by yourself. You cannot get out of the sub without a crew on the outside letting you out."
