Just read on PPRUNE that two days ago, a Cathay 777 had to make a emergency landing at a military airbase on a island called Shemya in the Aleutians! Says that there was smoke in the cockpit. Reading further someone posted it was a cooling fan in the cargo hold which caused the smoke.
Here's a video recorded by one of the passengers - compelling stuff as they were told to wear their life jackets in the event of having to ditch!
https://www.youtube.com/watch?v=KivHgCeJgiI&feature=youtu.be