Titanic sub: Search teams race against time to find missing vessel

Search teams are racing against time to find a tourist submersible that went missing during a dive to the Titanic's wreck on Sunday.

Five people were onboard when contact with the small sub was lost about an hour and 45 minutes into its dive.

The rescue operation is continuing in the mid-Atlantic but there has been no sign of the vessel so far.

US and Canadian agencies, navies and commercial deep-sea firms are all helping the rescue operation.