How can death result from tooth decay?!

How can death result from tooth decay?

I read on a newswire that a 12-year old boy died as a result of an abcess in one of his teeth. Apperently the abcess travelled all the way to his brain. How can this be possible? I also read that some Egyptian pharoahs experienced this and this type of tooth decay lead to their demise. Luckily, I read too that this type of phenomenon is rare. If someone has any insight as to how this is possible, please let me know. I have children I take regularly to the dentist for checkups, but if one of them were to complain of a toothache I'd cringe at the thought of what may happen. I'd take them immediately to the dentist to take care of the problem. I guess this too can serve as something someone too can learn from this post. I'd appreciate any answers. Thanks.

Perhaps the most serious consequence of an untreated dental infection is called Ludwig's Angina. As an infection grows it will spread. Most times a spreading tooth infection or abscess will eat a hole through the jaw bone and then through the gums. The gums will swell and eventually the infection will eat a hole through the gums and will drain into the mouth.
However, the infection can take a different route. it can spread into deeper tissues or it can spread into several "spaces" that are present in out head and neck. Will it is rare, an infection can find a path to the brain, or it can head toward the lateral pharyngeal space for instance. As it grows in this space, a person's throat can bulge and the pressure of the infection can restrict the airway, cutting off the breathing.
Deep neck infections are a rare but potentially fatal complication of pulpal abscess of the teeth. However an infection can progress rapidly from a toothache to a life-threatening infection.