It's one of those white-dust pavements that we have here.
I look back - and where my heel was there's a heel-shaped hole.
I look down the hole, and it opens into a BIG hole underneath.
Wow, that was some rain, that undermined the pavement...!
Later, on the way back from the bus-stop, we see a traffic cone over where the hole was.
I moved it a little to look down the now ENORMOUS hole !
Wow ! If it had been the ball of my foot rather than my heel that could have been a broken ankle pretty easily !
That's why you'll often see me walking down the middle of the road or in the cycle-path. It's safer !