In one of the documentaries hosted by Morgan Freeman, a reference was made that just like an ordinary three-dimensional object like a ruler has scratches and cracks, in the same way there might be minuscule loops in space-time. My question is this: If many bodies of extremely high densities are brought close together, will it deform the space-time fabric and hence create a permanent loop in space-time that might be accessible if ever achieved?
Spacetime is infinitely stretchable - in fact at the singularity in the centre of a black hole the spacetime curvature becomes infinite (though quantum gravity probably intervenes before the curvature actually becomes infinite). Spacetime cannot "snap" or "rupture" no matter how heavy the masses involved.
I can't think of anything in General Relativity that matches your description. Just possibly something like this may happen in quantum gravity. See http://en.wikipedia.org/wiki/Quantum_foam for more info, though note that the idea of a spacetime foam is purely speculative at the moment.
I believe string theory allows topology change to occur, and I suppose this could be viewed as a "tearing" of spacetime. However I don't know enough about this area to comment.