It can form in seconds.
a caverns roof becomes too thin to hold whats on top of it and eventually falls in to from a sinkhole
A sinkhole will eventually form
often sinkholes becomes plugged by sediments and later gets filled with water forming sinkhole lakes
with sugar cubes as limestone and grahm crackers as top soil...pour water on top, and watch the sinkhole form
the sinkhole got bigger
There is no abstract noun form for the concrete noun'sinkhole', a word for a physical cavity in the ground.The noun 'sinkhole' is sometimes used in an abstract context in relation to approaching a danger or ill advised situation (You can't afford to invest in a sinkhole like that.)
A sinkhole forms.
A sinkhole provides drinking water!