One argument however, isn’t vague at all and can date the end of Modernism to the minute. According to Charles Jencks, you can date the death of the modern movement not just to the decade or to the year, but to the minute; when the ‘Pruitt-Igoe’ apartment complex was demolished at 3 PM on March 16, 1972 to be precise.
At the time of its creation architectural magazines went crazy over such a masterpiece and it won awards. Unfortunately the tenants caused the place to become rather run down. And because of this, “major structural alterations” where needed, and by that they mean they demolished it. So with the fall of the ‘Pruitt-Igoe’ apartments was the fall of Modernism. Though I’m sure people will argue about that as well.
The modernism and postmodernism date quote I acquired from: http://www.buzzle.com/articles/214493.html
And you can view the ‘Trouble in Utopia’ sequence at: http://www.youtube.com/watch?v=cd7VOz_Wstg