Swellings in the ground and major horizontal cracks in the brick facing integrated with the supporting wall had appeared in the gymnasium of this establishment built in the 1970s. This damage appears to reveal a deterioration of the structure that could originate from a problem with the ground. As the client did not know how the damage identified would evolve nor whether it would be necessary to ensure safety arrangements, the client decided to implement protective monitoring. The in-depth structural study carried out by OSMOS showed that the cracks were not spreading. The client was thus able to better understand the need for major consolidation work to ensure the stability of the school.