I was -way- too late to even sign up for this, and I don't quite have the fortress building skills (or the ambition) to do this, but I had an idea...
First, make the standard fortress held up by only a single support, but in this case, the big red lever of doom is NOT going to be hooked up to the support. Instead, hook the lever up to another support that, when removed, will cause a cave-in over the majority of the fortress's masterpieces. This should cause tantrums. Now, if the wiki lever article is correct about tantruming dwarves pulling levers, then put a lever in the meeting area and hook it up to the bottom support. If a tantruming dwarf will pull levers like the article says, then SOMEONE should eventually pull it without you telling them to do so. Use high-value mechanisms to make it look like something to make dwarves happy, so that it is as seemingly innocuous as possible.
If tantruming dwarves will NOT pull levers (or if you just don't want to involve another lever), then instead put your meeting area somewhere above the critical support, then have another support in the meeting area that, when knocked over, will cause a cave-in that punches through all the layers of the fort below it then knocks out the floor that is being held up by the bottom support, causing the rest of the fort to collapse.