Well, the question has somewhat been answered before, but there's one part missing, which - I'd think - is in conflict with the physical laws.
The earlier reply says that the gravitational pull even at the event horizon is so big, that not even the other forces can overcome this. So far, so good...this part I can accept.
However, what makes it possible for the black hole to appear in the first place? In this situation, the gravity between every single atom would have to fight against the electromagnetic force in order to compress the atoms sufficiently to create a singularity. Once the singularity is there, the gravitational pull becomes infinite - but how the he** does the electromagnetic force allow the gravity to create the singularity in the first place? I'd say that since the strength of gravity is directly related to the amount of mass - the more mass, the stronger the gravitational pull...but the same amount of mass generates millions of times stronger electromagnetic resistance between the atoms...or, did I misunderstand something completely here?