Living with roommate is a fabulous experience. But some times it gives terrible experience also. I faced this problem when my roommate left my Chicago apartment with out giving any prior intimation. So everybody should take some steps to avoid this problem. If your roommate has left during the middle of a lease or without giving a proper notice in a month-to-month tenancy, leaving you liable for all the rent, your personal relations will be rocky at best. So a housemate who wants to go away in the middle of a tenancy is legally responsible, if she is a month-to-month tenant, for giving the landlord proper written notice and paying rent through the end of the notice period. Otherwise all tenants are liable for violation of lease or rental agreement. If they live with out notice you might be face money problem to pay the full rent so you can assure the landlord that you can promptly bring in a good, law- and lease-abiding new co-tenant, you might be able to salvage your tenancy. In the meantime, you may need to ask permission to pay the rent late or in installments. Or, ask the landlord to use the departed tenant’s share of the security deposit to help pay the rent until you find an acceptable replacement.