Here are the key things to look for in the Titan investigation, according to experts

One week after the world first learned the Titan submersible had gone missing on its way to the Titanic wreckage, investigators are beginning the search for answers about how and why it imploded.

Investigations are happening in Canada, the United Kingdom, France and the United States. Mapping the sea floor and debris fields near the Titanic has begun.

Tom Maddox, founder and CEO of New Jersey-based Underwater Forensic Investigators — a team that works to recreate accident scenes for analysis and reporting — said the debris on the ocean floor will help paint a picture of what could have happened to the submersible.

"The debris field itself tells a story. Where the parts are, how far apart they are, what direction they're aligning in," Maddox told CBC News Monday.

"Just like an airline crash, they may try to reassemble the sub to put the parts together like a puzzle to determine where the failure point was. In the case of a massive implosion that's not going to be an easy task because much of the craft would have disintegrated."

All five people who were aboard the submersible are presumed dead. U.S. Coast Guard Rear Admiral John Mauger, who led the search party for the vessel last week, has visited St. John's to speak with the families.

Eugen Abramovici, a former aerospace engineer who works in failure analysis — assessing materials and how they fail — believes the materials used to design the submersible will be key in the investigation.

The vessel was made with a combination of titanium and carbon fibre. Abramovici said titanium is able to withstand the pressure at the depth of the Titanic, but carbon fibre doesn't share those same qualities.

"Carbon fibre, which is practically 10 times thinner than the human hair, has a great resistance when you pull it apart in tensile, but does not have such a great resistance when you compress it. And this is exactly what's happening in this situation," he said Monday.

Abramovici said combining the two specific materials is problematic, especially with the presence of salt water.

"[Carbon fibre and titanium] can create electrical currents exactly like the battery in your car. So the miniscule electrical currents develop between these two materials, [which] may effectively melt or destroy the epoxy," he said.

The method by which the vessel was constructed will also be a key factor, Abramovici said.

He believes the submersible was likely manufactured through filament winding, the process of spooling carbon fibre around the cylinder of the vessel to build tension and a tight seal.

Spools of carbon fibre often come pre-epoxied, he added, which starts to solidify the second it is exposed to air. In a case like the construction of the submersible, he fears the epoxy may not have properly bonded with some layers of the fibre.