An estimated 80 kilograms of concrete fell off Zaha Hadid’s Library and Learning Center at the University of Economics and Business in Vienna last week, according to Austrian newspaper Die Priesse .

No one was injured when the chunk of concrete fell on Friday, and contractors are now investigating how it happened, while parts of the main entrance and surrounding pathways have been closed off, FastCo Design reports.

The incident follows from another similar instance last year, when a piece of fibreglass-reinforced concrete fell to the ground outside the building’s entrance – a fault that was put down to an “assembly error”.

Opening in October 2013, the leaning polygonal block of the Library and Learning Center is the heart of the new University campus, and features an angled black volume that cantilevers over the entrance. The straight lines of its exterior separate as they move inward, becoming curvilinear and fluid and generating a free-formed interior canyon.

The €87,800,000 project won the Royal Institute of British Architects’ (RIBA) European Award in 2014. Vasko und Partner Ingenieure were the structural engineers of the project, and ARUP Deutschland GMBH the facade engineers.

Images: Iwan Baan and Roland Halbe. Source: Zaha Hadid Architects