Break Lease Michigan Safety Concerns?

I signed a lease for a house in Michigan for one year about 4 months ago. About a week ago, my door was broken down by some aggravated guys and a prostitute and they stole some bikes and aulted my guests outside the premise. We called the cops and after some time the door was replaced. But they keep coming back, verbally threatening us, jostling the door, and have broken the windows in my roomates car. The landlord is completely unhelpful to us lest he get his money and wont consider subletting. How the hell do i break this lease?