If you destroy a ballistic missile, the debris will mostly remain on a ballistic trajectory, raining down on what would have been the target.
There's no reason to believe that the radar got destroyed at all. The explosions on the ground were confirmed to be hits on the airport terminal (aftermath pictures are available). Obviously, no part of a Patriot system likely to be inside a building.
Last I heard though, those hits were caused by normal Kalibr cruise missiles. It is a bit concerning that those got through, hopefully they learn from it. But not surprising, because it is challenging for a radar to search for objects both above it and at ground level around it simultaneously.