The first place to look is your lease. There should be a clause for "Casualty Damage" or something along that line. It should state how and when the lease can be terminated. Most Casualty Damage clauses allow only the tenant to terminate the lease as the landlord has a legal obligation to make repairs and keep the rental premise in habitable repair.
In Minnesota, the state has adopted the URLTA and that states a tenant may terminate the lease by moving out and notifying the landlord in writing within 14 days if the tenant determines that the premise is not habitable. If the place is partially habitable, the tenant may occupy at an abated rent till repairs are completed.