Sawz:

Definitions can be formed by describing actions (the process of falling apart is called a collapse) or states "When it was finished collapsing the tower was completely collapsed"). Your inability to deal with this facet of language has glued you to a single definition of a word which may only be applied to a terminal state. But that is a narrow view of themeaning of the word. A quick search using the Define: function of Google, for example, brings up:

"# break down, literally or metaphorically; "The wall collapsed"; "The business collapsed"; "The dam broke"; "The roof collapsed"; "The wall gave in"; "The roof finally gave under the weight of the ice"
# break down: collapse due to fatigue, an illness, or a sudden attack
# fold or close up; "fold up your umbrella"; "collapse the music stand"
# crumble: fall apart; "the building crumbled after the explosion"; "Negotiations broke down"
# an abrupt failure of function or complete physical exhaustion; "the commander's prostration demoralized his men"
# cause to burst; "The ice broke the pipe"
# a natural event caused by something suddenly falling down or caving in; "the roof is in danger of collapse"; "the collapse of the old star under its own gravity"
# crack up: suffer a nervous breakdown
# flop: the act of throwing yourself down; "he landed on the bed with a great flop"
# lose significance, effectiveness, or value; "The school system is collapsing"; "The stock market collapsed"
# crash: a sudden large decline of business or the prices of stocks (especially one that causes additional failures) "

I have underlined the ones relevant to this discussion.

A