"ultimate collapse" is correct and usable in written English.
You can use it when you want to refer to the final and absolute destruction of something. For example, "The country suffered an ultimate collapse after years of political turmoil."
Prosecutors have said the charges against Mrs. Fastow -- involving the under-reporting of some $200,000 in personal income over several years -- played no role in the ultimate collapse of the Enron in 2001, and ultimately cost the government nothing.
Civilization might even be hastened to its ultimate collapse.
And MG Rover's ultimate collapse notwithstanding, the 75 was actually a good car.
He was alluding to the fact that he resigned last August, before Enron's ultimate collapse.
Two demands from Vale Inco are, in the union's view, responsible for the ultimate collapse of the talks.
Considering history a cyclical process, Gumplowicz denied that social planning and welfare measures can save societies from ultimate collapse.
The ultimate such collapse occurred just five years ago this week, when the crash of Lehman Brothers revealed the rot in the entire system, and one over-leveraged domino after another fell.
The load-slip diagrams obtained from lab tests are employed to calculate the slip modulus of the connections for serviceability, ultimate and near collapse cases based on Eurocode 5 recommendations.
In week 7 when they fell to the Arizona Cardinals, in a hard fought but ultimate total team collapse in the fourth quarter, the team claimed that with "better execution and protecting of the football" they would come back the following week and be better.
Distance has totally collapsed, and the twin towers are the ultimate metaphor for that collapse.
The aim of the experimental study was to determine the influence of brace and gusset plate properties on CBF response from serviceability to ultimate limit states, including collapse.
