Crash clock says satellites in orbit are three days from disaster (newscientist.com)

It would be ironic if Starlink made Musk's goals of getting to Mars impossible because of an inescapable debris field.

I have trouble comprehending how a collision would happen, in 3d space, even with a "14000 starlink satellites" (16k square miles each, on average), with something like 100ft being enough for them to pass over each other.

I thought most of the maneuvers were to maintain large margins of safety, not prevent definite collisions.