With a blast of air horns from watching dignitaries, demolition began last week of the old Gottschalk's building to make way for the Burien Town Square. A sales presentation center featuring a full-scale condominium model will open in June. Announcements will begin this spring of businesses that have signed up to be a part of the project. The square is set to have more than 300 condos and apartments, retail shops, restaurants, a new city hall/regional library and public plaza.