The Titan submersible: when is tourism too extreme?

This week, the world has been captivated ( and wrapped up in hope) by the tragedy of the five people who've died in an attempt to visit the wreck of the Titanic.Jon sits in for Lewis this week and asks whether extreme tourism is going too far - whether we should push the boundaries of exploration (even if at potential great cost to others) and why the public; and the media, have been transfixed by the story.And we speak to Peter Kyle, Shadow Northern Ireland Secretary, on the anniversary of Brexit.