I wondered about this because the following is stated on https://en.wikipedia.org/wiki/Gravitational_singularity : "The laws of normal spacetime could not exist within a singularity" and therefore this suggest there is no coordinate system defined at that point/region, or if you like no 'normal'...
Since the center of a black hole is defined as a singularity and space-time collapses at that point (assumption) is it possible to define this point in 3D coordinates? In other words, is it possible that our universe can not be described as a 3D space but rather as a space with 2.99... dimensions?