We knew this day would come.  The Memorial Elementary School on Lincoln Street began its final razing last week, when a litany of heavy machines arrived after staff had cleaned everything out worth taking.  Student lockers were packed and returned to a parade of parent vehicles organized by last names and the building was emptied.  By Tuesday, there was nothing standing from the old school.  The first students arrived at Memorial School in 1953, when it was swanky new.  And it served the town’s young people well.  Next fall students in kindergarten through fifth grade will report to the newly built “half” of the project, which is nearing completion after a year of construction by the team at The Rich Companies.  The second half will be built on the footprint of what came down this week.  The entire school project is scheduled for completion by Fall 2021.