AFP news agency reported on June 21 that US and Canadian coast guard ships and planes are searching an area of ​​nearly 20,000 ^square kilometers in the Atlantic Ocean in search of a submarine that went missing while exploring the wreck of the Titanic.

The area is larger than the US state of Connecticut, where the submarine Titan of the US company OceanGate Expeditions went missing on the morning of June 18 with 5 people on board.

The 6.7-meter-long submersible was designed to dive continuously for 96 hours (4 days) and lost contact with the Polar Prince surface ship after diving about 640 kilometers (400 miles) off Newfoundland, Canada.

A US Navy spokesman said special equipment for lifting heavy objects in the deep sea was mobilized to join the rescue effort from the evening of June 20.

The Pentagon said it had dispatched a third C130 and three C-17s, while the French Oceanographic Institute said a deep-sea robot and experts would search the area from June 21.

Rescue efforts are underway, while the incident has prompted many to recall a 2018 lawsuit over the firing of OceanGate Expeditions' former director of marine operations after raising safety concerns about the Titan submersible.

David Lochridge raised the issue of the company's "experimental and untested design of Titan" in a court filing. The Titan submersible lost contact with the surface ship less than two hours into the dive.

OceanGate Expeditions charges a $250,000 (VND5.88 billion) entrance fee per passenger. Among the passengers on the submersible are British billionaire Hamish Harding, a Pakistani businessman, his son and two others.