This is your layman's fantasy and intuition, right? Or how would you support these claims?
For starters:
1. How do you know all 4 corners went down simultaneously?
2. Support columns are never "separate". They are always connected. You know that the interior columns did not fail simultaneously but in sequence over a period of several seconds as evidenced by the fall of the two penthouses, right? It turns out that once lateral support is gone, the rest of the interconnected columns will fail in very rapid succession, i.e. very close to simultaneously. These things can be simulated in computers and have been simulated. You can do experiments that inform your intuition, such as stomping an empty beer can.