If anything it's a minor coincidence that the World Trade Center was destroyed precisely 28 years after a Chilean revolt.
The two events have absolutely nothing in common with one another other than sharing an arbitrary day and month of the year.
They were both major centers of economic control.
The fact that the year only has a mere 365 days has always been a boon to numerologists...
Plus, whether it's a coincidence or not, one event overshadows the other - Pinochet's coup and destruction of one possible future of humanity (Edit: the USSR was having high hopes in relation to Cybersyn). Google for 9/11, you will see only one and not the other.