Denise's Mac Mini shut down the other day and issued a "panic report." Leo says that something just crashed and the Mac shut down on it's own. It's called a 'kernel panic', and it's not that unusual. It could even have been a power surge that caused it. Generally, it's a hardware issue, but if it only happens every so often, like every six months, it's nothing to really be concerned about at this point.
It could be a hardware issue, or a driver issue. It's much more likely that this is a hardware problem, though. The first thing he could try is clearing the "PRAM". Restart the Mac by holding Command, Option, P, and R.
He can also try booting from his system disc. If that works, then he'll know that his logic board is failing and that's an expensive repair. Hopefully Alex has AppleCare. Otherwise, it may be more worth it to just get a new Macbook.
Kernel panicking is the blue screen of death for Apple products and is generally caused by a hardware issue. He'll need to take it in to have it looked at.