What Caused the Cretaceous Extinction?

I believe it was more so like an apocalypse rather then a nuclear explosion, And most likely the asteroid broke into pieces in the atmosphere, Id imagine that the impact from the KT boundary probably blasted all surrounding dinosaurs a few KM or so *just a theory* Or perhaps there was no dinosaurs there... *look at north america... only about 42% of it is habituated....Think the rockies farm land... forests... all unoccupied* Also following up on the apocalypse theory *theres more then just zombie apocalypse mans more fascinated however by zombies* A basic apocalypse would be some sort of disaster *this is where they all branch out* most of the time the disaster wipes out most of the food/water supply Then its only a given time before all victims are destroyed *think of it like this herbivores eat plants, plants die out, herbivores start to die, carnivores eat herbivores, herbivores die out, carnivores eat carcass's, carnivores die out extinctions finished, new life begins* this happens a lot in the world of nature, evolve or die, its even happening today *though i cant think of any good examples...* I also believe desease would've played along with they're destruction, the asteroid would've killed a few and would've begin to kill them off by the hundreds but this takes a few days, reckon weeks... Truth be told.. we dont know *not unless you got a tardis OR delorion on hand *

Right, like something that happened slowly over time

Yes but not too long, remember the shock wave from the asteroid killed a lot of things, it started tsunamis earth quakes and so on... AT most id give it a month to kill every dinosaur on the planet

Right. Pretty nasty forces at play when you can wipe out all the dinosaurs on the Earth in a month. Not as bad as the Permian though...