Canadian authorities launched Saturday an investigation into the implosion of the Titan submersible that killed the five men aboard.

"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 probe could take between 18 months to two years.

TSB investigators on Saturday 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 probes 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 U.S. Coast Guard said Thursday that all five people aboard the submersible had died after the vessel suffered a "catastrophic implosion."

A debris field was found on the seafloor, 500 meters (1,600 feet) 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."