Section 5309 - Fire and casualty damage; landlord obligation and tenant remedies(a) If the rental unit or any other property or appurtenances necessary to the enjoyment thereof are damaged or destroyed by fire or casualty to an extent that enjoyment of the rental unit is substantially impaired, and such fire or other casualty occurs without fault on the part of the tenant, or a member of the tenant's family, or another person on the premises with the tenant's consent, the tenant may: (1) Immediately quit the premises and promptly notify the landlord, in writing, of the tenant's election to quit within 1 week after vacating, in which case the rental agreement shall terminate as of the date of vacating. If the tenant fails to notify the landlord of the tenant's election to quit, the tenant shall be liable for rent accruing to the date of the landlord's actual knowledge of the tenant's vacating the rental unit or impossibility of further occupancy; or(2) If continued occupancy is lawful, vacate any part of the premises rendered unusable by fire or casualty, in which case the tenant's liability for rent shall be reduced in proportion to the diminution of the fair rental value of the rental unit.(b) If the rental agreement is terminated, the landlord shall timely return any security deposit, pet deposit and prepaid rent, except that to which the landlord is entitled to retain pursuant to this Code. Accounting for rent in the event of termination or apportionment shall be made as of the date of the fire or casualty. 70 Del. Laws, c. 513, § 2.;