Tube failure -- what would happen in worst case?

I don't want to scare anyone,but fire is always possible.A simple coupling cap shorting out can cause a tube to have thermal runaway.If a tube starts glowing orange,shut if down(the gear) as fast as possible.Solid state amps,tv's, and other electronics all have risks too.Homes burn down for various reasons,a lot are electrical,or electronic failures.

As has been said, a fire is the worst thing that can happen.

Apart from that, I've seen amps take a transformer (power or output) out. That's a repair you don't want to get into.

Thanks for all.
I did not bother to bias my tube amp, and I am selling one (Chinese made) and get an amp with auto bias feature (BAT vk60).
Any way, is this a good reference for biasing?
http://www.aikenamps.com/Biasing.html
Any of you have other source?

I did not bother to bias my tube amp

Why not?Just curious.

I guess I was lazy and ignorant. I assumed that a new tube amp was factory biased and I should not fiddle with it, and also I did not want to damage my amp by screwing up. Now I feel like I need to know more about biasing.