The main support ship of the Titan submersible has returned to a Canadian harbour following the deep-sea vessel's fatal implosion.Flags on board the Polar Prince were at half-mast as it arrived at the port in St John's in Newfoundland on Saturday morning after four passengers and the pilot of Titan were killed in the incident.

The main support ship of the Titan submersible has returned to a Canadian harbour following the deep-sea vessel's fatal implosion.Flags on board the Polar Prince were at half-mast as it arrived at the port in St John's in Newfoundland on Saturday morning after four passengers and the pilot of Titan were killed in the incident.