From a FAA website:
"February 1942..Build (sic) by the City of Miami on what would become "Masters Field", then being constructed on a vast area bounded by the Seaboard Coastline Railway, NW 27th Avenue, NW 103rd Street and NW 119the Street. The new airport was to have five runways, some as long as six thousand feet, with the passenger terminal on the east side of the airport connecting directly with the Pan American Seaplane Base at Dinner Key via 27th Avenue. This structure was the first actually designed as a control tower, but, unfortunately, had a partial glass roof with no ventilation or air conditioning. The CAA staff occupied this facility in February 1942, and maintained it until it was turned over to the U.S. Navy as part of the Opa Locka Naval Complex in August 1942."