Neutron degeneracy pressure fails and nothing can stop its gravitational collapse. Infalling matter is shredded by powerful tides and crushed to infinite density. Call such objects Black Holes . Anything inside RS can never leave. Hides the singularity from the outside universe.
Gravity is the same as a star of the same mass.
If the Sun became a Black Hole, the planets would all orbit the same as before . He is carrying a laser beacon that flashes a beam of blue light once each second Jill is orbiting the black hole in a starship at a safe distance away in a stable circular orbit. She watches Jack fall in by monitoring flashes from his laser beacon. Flashes the laser every second by his watch. Sees a blue beam leave the laser.