No, you can't sue the landlord. A landlord is not responsible for the criminal actions of his tenants--or, indeed, for any harm they do either negligently or carelessly as well. One person is not resonsible for the harms or crimes done by another unless the first person him/herself contributed to or participated in them, and simply renting out space to another is not enough of a contribution or link to make the landlord liable. You can sue the actual attacker for your injuries or costs, as well as pressing criminal charges.