The Moulin Rouge - better known for its topless dance line - is now sans moulin as its well-known windmill fell from the roof in the early morning hours on Thursday.
Laurent Nuñez, head of the Paris police, told French broadcaster TFI that the cause of the incident remains unclear. There were no injuries.
The surrounding area has been cordoned off and experts are investigating the safety of the building.
Pictures showed that the damaged windmill wheel was lying in its entirety in front of the cabaret theatre. Three letters of the large Moulin Rouge signage were also torn off.
The wheel fell down between 2 am (0000 GMT) and 3 am on Thursday morning when the theatre was already closed, reported the BFMTV channel. There was no danger of the rest of the building collapsing.
The Moulin Rouge said the technology of the mill wheel is checked weekly and there were no anomalies. This is the first emergency at the Moulin Rouge since a fire in 1915, which ended up closing the cabaret for nine years, the broadcaster reported.
The Moulin Rouge, which celebrates its 135th anniversary in October, is the oldest cabaret in Paris and one of the city's landmarks. The house still gleams in sinful red, although the days when it symbolized frivolous Paris are long gone.
The attraction's clientele on Montmartre has also changed.
The bohemian crowd of yesteryear has given way to tourists from all over the world, and the half-naked dancers no longer only attract men in droves.
The Moulin Rouge is one of the most visited attractions in Paris.
The city's oldest revue theatre has become a journey back in time, starting in the foyer with its red velour tapestries.
A touch of Belle Époque also wafts towards visitors in the 850-seat auditorium: Art Nouveau lamps and mirrors and Litfass columns with Toulouse-Lautrec pictures.