The title is factually incorrect: the iceberg didn't hit the Titanic. The historical record clearly indicates that it was just chillin' out.
That's just a matter of your chosen frame of reference.
Clearly we didn't "hit" any issue, but we started experiencing an issue.
Using it as a noun is like saying "before the hit" or "before the issue". "Iceberg" is an adjective describing the type of hit.