he didnt predict it, people took his words out of context
The quatrain does not say "In the year of the new century and nine months," but instead reads "In the year 1999 and seven months, from the skies shall come an alarming powerful king" (Century 10:72). The fact is that in September of 1999 nothing at all happened like this which makes Nostradamus not only an unreliable prophet but a false one also. In fact, all of his quatrains have to be intrepeted to fit the event. Nostradamus is not a very reliable source of prophecy. You would do much better to consult the bible.
This phrase has been interpeted to mean "twin brothers" being "torn apart": "Two royal brothers shall war so much one against the other". I don't believe this is a reference to the twin towers. (Century 3:97).
What about "The sky will burn at 45 degrees, fire approaches the great new city"? This is what it actually says: "The heaven shall burn at five and forty degrees, The fire shall come near the great new city...when they shall make a trial of the Normans" (Century 6;97). How does this fit in with what happened in New York? The fact is Nostradamus is a popular subject and therefore a money maker in book and video sales. Let's change a word here and there and see how amazing Nostradamus is. If you really want to know what the future holds, study the bible. Conclusion: Nostradamus did not predict the fall of New York's twin towers. It is an elaborate hoax.