Investigators board the Polar Prince as it returns to port.
Canadian investigators boarded the support ship used to launch the Titan submarine in an attempt to determine what caused the vessel’s devastating implosion.
The Polar Prince docked in St John’s, Newfoundland, with its flags at half-mast on Saturday.
In the harbour, another boat was seen hauling the Titan’s launch platform.
The Titan was on its way to the Titanic wreckage when it broke apart, killing all five people on board.
At 08:00 (11:30 BST), St John’s residents gathered around the cannon atop Battery Lookout to witness the Polar Prince return to port. Investigators with hard hats and high-visibility jackets stepped aboard as some passengers disembarked.
The Titan’s support vessel, the Polar Prince, had towed the submersible out to the area in the North Atlantic where it made its dive on Sunday, roughly 400 miles from St John’s.
Members of the support crew and several victims’ families were on board. It also assisted in the search for the Titan after it lost touch approximately one hour and 45 minutes into its descent.
What will happen next in the Titanic sub operation?
St. John’s contemplates a familiar sorrow in the loss of Titan.
Among the deceased are the owner of Titan, a billionaire, and his son.
On Thursday, parts of the submersible were discovered on the ocean floor, approximately 1,600 feet (487 meters) from the bow of the Titanic catastrophe.
On Friday, Canada announced the initiation of a safety probe. Other countries’ government agencies may join in, although it is unclear who will head the inquiry at this time.
In addition to the involvement of the Polar Prince, officials will examine the materials used to construct the sub’s outer walls, according to experts.
Since the news of the tragedy came, industry experts have stated that they had previously voiced concerns about OceanGate, the business that owned the Titan and whose CEO Stockon Rush was on board at the time of the accident.
According to emails obtained by the BBC, Mr Rush dismissed concerns raised by one expert as “baseless cries.”
Shahzada and Suleman Dawood, Hamish Harding, and Paul-Henry Nargeolet were also on board the Titan.