Le Corbusier’s Chapel of Notre Dame du Haut in Ronchamp, France, one of the most important works of 20th-century ecclesiastical architecture, was severely damaged by vandals on Friday, January, 17. The suspects stole a concrete trunk, damaged a door and smashed a stained-glass window that was hand-finished by the Franco-Swiss architect with an original illustration. France’s Department of Historic Monuments has deemed the window to be irreplaceable.

The chapel is a unique work for Le Corbusier as it is smaller in scale and exhibits curvilinear forms as well as traditional iconography. Le Corbusier is credited with changing the face of urban architecture and is known for his efficient yet austere style.

The Chapel of Notre Dame is still used regularly by its adjoining abbey.