Canadian authorities have begun an investigation into the implosion of the Titan submersible, whose disappearance near the wreckage of the Titanic with five men on board had set off a multinational search-and-rescue operation.
"Our mandate is to find out what happened and why and to find out what needs to change to reduce the chance or the risk of such occurrences in the future," said Transportation Safety Board (TSB) chair Kathy Fox.
"We know everybody wants answers, particularly the families and the public," she told reporters in St John's, Newfoundland.
The full investigation could take between 18 months to two years.
TSB investigators yesterday boarded the Canadian-flagged Polar Price cargo ship, which had set sail from St John's last weekend to bring the ill-fated Titan to its launch point in the north Atlantic.
The Transportation Safety Board routinely investigates air, rail, marine and pipeline accidents with the aim of improving transportation safety. It does not assign fault or determine civil or criminal liability.
The US Coast Guard said on Thursday that all five people on board the submersible had died after the vessel suffered a "catastrophic implosion."
A debris field was found on the seafloor, 500m (1,600ft) from the bow of the Titanic.
Meanwhile, the Royal Canadian Mounted Police (RCMP) was looking into whether any criminal laws had been broken in the chain of events that led to the deaths of the Titan adventurers.
The investigators' job is to determine "whether or not a full investigation by the RCMP is warranted," said Newfoundland and Labrador Superintendent Kent Osmond.
"Such an investigation will proceed only if our examination of circumstances indicate criminal federal or provincial laws may possibly have been broken."
Read more:
Ships return as Titan sub recovery operations begin to wind down
Crew on missing Titanic sub died in 'catastrophic' event - US Coast Guard
