Going up: Construction has started on Boatmen's Bank Building at 7800 Forsyth Blvd. in Clayton. The building will house the main offices of Boatmen's Bank of St. Louis County (formerly Metro Bank/Clayton), and Boatmen's Trust Co. (formerly Metro Trust Co.). Boatmen's will occupy the first four floors or about one-half of the building which is being developed by Bakewell Corp.