The search for the Titan, which has been missing since Sunday, entered its fourth day on Thursday. The possibility of finding the occupants alive is still being explored, as noises are being detected in the areas being probed. The US Coast Guard has so far searched 10,000 square miles of the Atlantic Ocean, with no luck. The five people onboard the submersible when it went off the radar were British-Pakistani billionaire businessman Shahzada Dawood, his son Suleman, Hamish Harding, Stockton Rush, and French explorer and navy commander Paul-Henry Nargeolet. The Titan’s expedition, which costs $2,50,000 per person, had begun from St. John’s, Newfoundland, Canada.

The craft has an emergency supply of oxygen that can last approximately 96 hours. Some possible scenarios that may have caused the submersible to fail include the malfunction of its communication equipment or ballast system that controls its descent and ascent. Its limited supply of air is also a threat, as it will soon lose the ability to scrub enough carbon dioxide, and will not be able to sustain life. Hypothermia is also a danger if the vessel’s batteries run down and are no longer able to run heaters. The US Coast Guard continues to race against time through its search operations in the Atlantic Ocean, hoping to find the occupants of the Titan alive.