Investigators pull submersible debris on shore in hopes of finding clues about catastrophic failure during descent toward Titanic wreck , killing all five on board

Questions abound on who has authority to lead what is likely to be a complex investigation involving several countries

Arthur Loibl, 61-year-old adventurer from Germany, describes 10.5-hour voyage inside 'metal tube a few meters long with a sheet of metal for a floor' lit by fluorescent glow stick

'Titanic' director and renowned deep-sea explorer says submersible was source of widespread concern in close-knit ocean exploration community

Officials say debris found on ocean floor near wreck of the Titanic indicates submersible missing since Sunday was destroyed

Breathable air believed to have run out on lost submersible carrying 5 people to deep sea wreck; robot reaches ocean floor as rescuers search for source of 'banging noises'

Responders focus on area where underwater sounds heard, insist they are 'hopeful' for rescue, as effort hits critical stage with only hours left for 5 people in submersible

But US Coast Guard doesn't elaborate on whether the sounds indicate some of the 5 onboard the Titan are alive, as rescuers scramble to find vessel that has 24 hours of oxygen left

US Coast Guard leading the search for Titan and the five people aboard, noting that it is 'a challenge to conduct a search in that remote area'

OceanGate Expeditions, which has run annual expedition since 2021, says it is determined to find five people aboard vessel