What happens to the blueprints to houses that get torn down?

I would like to get the blueprints to my old childhood home. it was just recently torn down, but i would still like to get the blueprints to the house.








Blueprints are the property of the architect who designed it. Can you track him down?
There should still be something on file at the building department
from when the house was built.
Copies are usually available for a fee.
Better hurry.
They just might discard them when 'demolition' permits come through.