Is it possible to be released from a lease over a roach infestation?

Our landlord is not fixing a roach infestation that has been going on long before we moved in. He is also not put locks on the front doors to the building and we have been having an issue with a homeless man entering the building at night and sometimes using the basement as a bathroom. We have been trying for months to get him to remedy the roach situation and he hasn't. We don't not feel safe living here anymore and would like out of our lease to just move on. They have known about the infestation for a long time, its coming from the woman's apartment below us, yet before we moved in we asked if the apartment has any problems and they told us there are no problems and everything is clean. Do we have legal grounds to break our lease and move out, as well as get our security deposit back? This is all we want at this point. The stress of this has begun having adverse affects on our health and we do not know where else to turn. Thank you