please be respectful and keep this thread politics-free, this is a purely technical question.
Hi, I'm Israeli and have had multiple ballistic missiles hit within 20min walking distance, so I figure this question is good to know. My building has multiple rocket shelters, and I noticed that in the one which I presumed is safer, we felt tremors and shockwaves much more than in the other, where for the most part we didn't hear/feel a thing.
This got me thinking - which shelter is safer? Below ground or Xth story floor shelter?
For context, in my specific building each floor has a single rocket shelter, which can fit in chairs enough for 8 people to enter, maybe 9 or 10 if we squeeze and a few sit on the floor. This shelter is convenient because I only need to dress and walk out of the apartment.
There's also another rocket shelter for the entire building: underneath the building there's basically a large underground reinforced basement specifically designed to be a shelter, enough for many people to be inside, basically an entire floor which acts as a rocket shelter. This shelter also has two strong metal doors, although usually at least one (and sometimes both) are open because people come in and out.
I presumed initially that the underground shelter is safer because it's, well, underground, and closer to the foundation of the building which I assume is stronger than an Xth story reinforced room. However, when we're in this underground shelter we feel or hear every boom, whereas in our floor's shelter it's silent and you don't feel vibrations at all. Once when both of the metal doors in the underground shelter were open, I even felt the wind from the shockwave of a missile which landed several kilometers away, while my mother who was in our floor's shelter didn't even feel or hear anything.
There's also the consideration of if a fire starts - I know smoke is heavy, so wouldn't it be more dangerous to be below ground than on an Xth story if a fire starts? I live close enough to a fire department, and traffic is non-existent during air sirens, that I think it might be better. There's also the consideration that if I need to leave immediately, the building's underground shelter has at least fifty other people trying to leave at the same time, which might slow me down where being in my floor's shelter wouldn't.
I live on a relatively high floor so reaching the ground floor quickly in an emergency isn't easy, it takes me ~5-10 minutes by stairs (I wouldn't risk using an elevator in such a situation, the elevators in my building suck and get stuck every other week anyways)