In most of the dreams that I look at, the dream people do not represent real people but are symbols of archetypes from the collective unconscious.  So it is with this dream.

In your dream, you work in a hospital.  This is probably a very good sign.  In the real world, a hospital is a place for helping the injured and curing the sick.  This dream hospital has a similar purpose in this dream.

Two floors of the hospital are underground.  Thus, the hospital would be especially good at helping archetypes, which come from the collective unconscious.  The unconscious is often represented in our dreams as a cave or some place that is underground.

The two floors that are above ground look like a church.  This is consistent with the spiritual function of many of our dreams.  And, it may also refer to the religious feelings of the dreamer.

Notice that the hospital has four floors.  The number four is the symbol of wholeness ? another good sign.

But, there is a problem; ?someone outside [is] shooting everyone.?  The man who is trying to shoot people is a symbol of your animus.  This is a fairly common problem that I see in many dreams.  It means that one archetype/dream person has become dangerous.  When this happens, it almost certainly means that the dream person has become violent because he wants your attention.     

When you are outside, he sees you.  You hide in a bathroom stall.  This is a good sign.  The bathroom is a place for eliminating impurities.  Thus, you are doing a spiritual cleansing. 

%%%%


The dream person is violent because he is jealous and wants more attention from you.  They way that you can cure his violent nature is the give him more attention.  You have already taken a big step in the right direction.  You are listening to your dreams and are trying to understand what they mean. 

The last thing that you want to do is to ignore these dream people.  When we do that, we are asking fro trouble.  These dream people want to be our helpers and our best friends.  But, they can not do this when they are ignored.

BTW ? as a part of your listening to your dreams, you might seriously think about starting a dream journal.  Something to think about.

Hope this helps.