Catastrophic collapse means that the vertical load bearing capability has gone to less than the burdened weight (all the structural margin has been used up by the fire-weakening of the columns). The way this happens is that first one column fails. The compressive load is then redistributed among the remaining columns at the speed of sound in the hot steel (probably close to 4000 feet/second). With one column gone, the load per column just got greater, and another column will fail. This is a chain reaction that will take only milliseconds to spread across all the columns, during which time the overburden would scarcely have moved. The underlying floor will have failed, the overburden falls at gravity acceleration, lands on the next floor, and the process starts all over again. Since the upper stories are massive, there is plenty of inertia to prevent it from tipping in the time it takes for the downward collapse.

I doubt other buildings have had occasion to collapse in just this way, which is the result of the structural core being rendered useless by heat-weakening from a tremendous fire.