During the siege of Vukovar the hospital was subjected to continual hostile fire despite a large red cross, placed on the hospital roof, indicating to enemy aircraft that it was a site protected by the Geneva Conventions. Nonetheless, during the three‑month siege shells fell on the hospital perimeter daily. Medical staff and patients were moved to the hospital basement where doctors worked in inadequate conditions and without essential medical supplies. On 20 November 1991, JNA personnel detained international observers in the town centre and, during that time, removed more than 260 people from the hospital; these were killed at Ovčara or elsewhere, and many remain unaccounted for. Today visitors can see in the hospital basement a multimedia presentation about the hospital during the siege of Vukovar and an accurate reconstruction of the basement as it was then.