The Titan submersible suffered a catastrophic implosion that experts say likely killed its pilot and four passengers instantly amid intense pressure in the North Atlantic’s deep waters.

In the days before the Titan vessel went into the ocean off the coast of Newfoundland, Canada, the 19-year-old university student accompanying his father on the expedition expressed hesitation about going, his aunt said in an interview Thursday.

At first, news that a submersible had gone missing during a voyage to the Titanic wreckage site ignited a wave of shock and concern. The five people on board, now presumed dead, faced a dwindling oxygen supply and a harsh and unforgiving environment deep underwater.

Ever since the Titan submersible went missing on Sunday while exploring the shipwreck site of the Titanic, it’s all I’ve been able to think about.

A renowned Titanic expert, a world-record holding adventurer and two members of one of Pakistan’s wealthiest families and the CEO of the company leading an expedition to the world's most famous shipwreck are facing critical danger aboard a small submersible that went missing in the Atlantic Ocean.