Passengers are unable to enter the station on Eversholt Street, between Camden Town and Euston, this morning (October 14).
The entire station has been closed, and Northern line trains are not stopping at Morning Crescent while repairs take place.
According to Transport for London (TfL), the structural damage is in the ticket hall area.
There has been no indication as to how long the closure will last, nor the extent of repairs needed.
Replacement tickets are being accepted on London buses via reasonable routes.
TfL has been approached for comment.
