On board, a rather macho admiral bellowed over the intercom that he didn't care about global warming - but his job was to keep watch over the waters around the US and there was now a lot of water where there used to be ice.

BBC: The 'big melt' at the roof of the world

We were returning from an afternoon safari when the first bell buzzed over the intercom.

BBC: Safari in Kenya without four wheels

Eventually, a police officer rang her doorbell and told her over the intercom to come down and identify her boy.

WSJ: NYPD program patrols inside private buildings