The Canada Lands Company is destroying the de Havilland Aircraft Building in Downsview.

 The completely gutted heritage building will be a satellite campus for Centennial College in Toronto. 
Downsview Park is a Canada Lands Company subsidiary.

The Government of Canada never wanted to "dispose of " Canadian Forces Base Downsview to a profit making Crown corporation that collects millions of dollars from residential and commercial real estate entities.
1.) "A number of Senators wanted to obtain some information on Parc Downsview Park...usually when the federal government declares a land surplus, it is turned over to Canada Lands Company Limited...However ND did not want to divest itself of the Downsview military base"(Google: Journals Issue 97, November 22 2005.).

2.)  "When we closed those bases, in particular Downsview, we said that the land would be retained in perpetuity for future generations, primarily as a unique, open, recreational green space. The reason we put primarily in there is that other ongoing uses would still be permitted...It was always intended for a portion of the land to remain in the title of National Defence so that if,God forbid, we were in an emergency situation whereby that land would be required for emergency defence operations, it would be there". (Google: Points of Order - June 11, 2001- Downsview David Collenette.)