Why would they spend money tearing it down if they.. ran out of money? Surely if they default on their loans the buildings would be sold to a new owner...?
I think thats part of the question, too. If you made a huge building but ran out of money and had to close it, who would be responsible for the building, and who would have to pay to have it torn down?
Here is a more likely outcome: http://www.gadling.com/2011/03/08/abandoned-caracas-skyscrap...
Note the case of the Ryugyong Hotel, demonstrating that such buildings can be abandoned for long amounts of time without anything needing to be done to them.