Can I break the apartment lease early if I no longer feel safe there?

No, not on the facts you presented. If all a tenant had to do to terminate a lease early was claim that "they no longer felt safe," then all leases would be subject to early termination and a fixed term lease would serve no useful purpose. If the apartment complex promised (i.e., in brochures or advertisements) 24-hour security, then complain in wiring to the landlord and that may form the basis for terminating tenancy early, but few apartments make those types of promises in writing. That does not mean, however, that you have no recourse. Hopefully, you have created a "paper trail," which means that you have sent written notices to the landlord/manager each time you encountered a problem. If the "traffic control gates" only functioned fifty percent (50%) of the time you have been there, then you may be able to file a small claims lawsuit against the landlord to recover a portion of the rent you paid because you did not receive what was promised to you (i.e., functioning control gates). This type of small claims action is best filed AFTER you have moved. Returning to your personal safety, you may need to spend some money for your own personal safety, which may mean moving in with a friend for a short time or renting another apartment (somewhere else, of course) and paying rent on two apartments for one or two months. I know that may be difficult and "isn't fair," but your personal safety has to come first.