Found this post over at A.R.F. and thought it was a good lesson in why Caps need replaced, particularly Electrolytics.
http://www.antiqueradios.com/forums/...p?f=2&t=209675
The first picture shows the can that exploded, the second shows the hole the can punched in the ceiling!
If you happened to be in the path of such a projectile it could do serious damage to your body!