Legal Question in Landlord & Tenant Law in California

You are in a fairly complicated situation legally. If the landlord actually maintained an unsafe building, he is liable to you for your loss from the robbery. Just because a robber can get in, though, doesn't mean the building was unsafe as a matter of law. In addition, if a landlord has an unsafe condition, you can only break the lease if he fails and refuses to fix it. Without knowing all the details, it seems you are saying he took reasonable steps to fix any problem by installing the steel door. If there are other unsafe condtions on the property, you will have to notify him and he will have to fail and refuse to fix them before you can even consider trying to break the lease. The only other thing you can do is take your chances and move out, giving notice to the landlord. You will still be on the hook for rent for up to a year, but the landlord will have to take all commercially reasonable steps to re-rent the property, and once he does your rent obligation ends. If he doesn't re-rent the property and tries to sue you for the rent for the rest of the term, he will have to prove he did everything commercially reasonable to find a new tenant, before he'd be able to collect from you. That's a big risk to you, but one you do have the option of taking.