Yes. It's possible. No crater bullshit is red herring. Could have dropped it right in the front door and into the basement. Then the crater would be inside the building with all of the shit blown outwards. Kinda exactly like what we see.
bomb smashes through masonry side of the building, drops through the floor into the sub basement, hits something hard, blows up, blast propigates through the tunnels and pushes them up and out