This was taken way back in my old work place.  http://www.youtube.com/watch?v=PnvnQsmZOG8

Took about 5 days to complelty burn out then the ends were glowing for like 10 days. 

It looks like the tube first burnt out, then the glowbottle starter contacts inside the bulb got stuck, which occurs often when the starter blinks for too long. Maybe after a 10 days long preheating, the ballast died.

I saw the same thing happened to a 2D fixture in a block of flats, a few years ago. The ballast really didn't like it. Nor did the residents of the flats who were woken in the night by the sound of fire alarm!

Fixture was a total write-off afterwards, along with the ceiling tile it was fixed to