Wash. Rev. Code § 59.18 § 59.18.595

(1) In the event of the death of a tenant who is the sole occupant of the dwelling unit:
(a) The landlord, upon learning of the death of the tenant, shall promptly mail or personally deliver written notice to any known personal representative, known designated person, emergency contact identified by the tenant on the rental application, known person reasonably believed to be a successor of the tenant as defined in RCW 11.62.005 , and to the deceased tenant at the address of the dwelling unit. If the landlord knows of any address used for the receipt of electronic communications, the landlord shall email the notice to that address as well. The notice must include:
(i) The name of the deceased tenant and address of the dwelling unit;
(ii) The approximate date of the deceased tenant's death;
(iii) The rental amount and date through which rent is paid;
(iv) A statement that the tenancy will terminate 15 days from the date the notice is mailed or personally delivered or the date through which rent is paid, whichever comes later, unless during that time period a tenant representative makes arrangements with the landlord to pay rent in advance for no more than 60 days from the date of the tenant's death to allow a tenant representative to arrange for orderly removal of the tenant's property. At the end of the period for which the rent has been paid pursuant to this subsection, the tenancy ends;
(v) A statement that failure to remove the tenant's property before the tenancy is terminated or ends as provided in (a)(iv) of this subsection will allow the landlord to enter the dwelling unit and take possession of any property found on the premises, store it in a reasonably secure place, and charge the actual or reasonable costs, whichever is less, of drayage and storage of the property, and after service of a second notice sell or dispose of the property as provided in subsection (3) of this section; and
(vi) A copy of any designation executed by the tenant pursuant to RCW 59.18.590 ;
(b) The landlord shall turn over possession of the tenant's property to a tenant representative if a request is made in writing within the specified time period or any subsequent date agreed to by the parties;
(c) Within the same number of days as required under RCW 59.18.280 , after the removal of the property by the tenant representative, the landlord shall refund any unearned rent and shall give a full and specific statement of the basis for retaining any deposit together with the payment of any refund due the deceased tenant under the terms and conditions of the rental agreement to the tenant representative; and
(d) Any tenant representative who removes property from the tenant's dwelling unit or the premises must, at the time of removal, provide to the landlord an inventory of the removed property and signed acknowledgment that he or she has only been given possession and not ownership of the property.
(2) A landlord shall send a second written notice before selling or disposing of a deceased tenant's property.
(a) If the tenant representative makes arrangements with the landlord to pay rent in advance as provided in subsection (1)(a)(iv) of this section, the landlord shall mail a second written notice to any known personal representative, known designated person, emergency contact identified by the tenant on the rental application, known person reasonably believed to be a successor of the tenant as defined in RCW 11.62.005 , and to the deceased tenant at the dwelling unit. The second notice must include:
(i) The name, address, and phone number or other contact information for the tenant representative, if known, who made the arrangements to pay rent in advance;
(ii) The amount of rent paid in advance and date through which rent was paid; and
(iii) A statement that the landlord may sell or dispose of the property on or after the date through which rent is paid or at least 45 days after the second notice is mailed, whichever comes later, if a tenant representative does not claim and remove the property in accordance with this subsection.
(b) If the landlord places the property in storage pursuant to subsection (1)(a) of this section, the landlord shall mail a second written notice, unless a written notice under (a) of this subsection has already been provided, to any known personal representative, known designated person, emergency contact identified by the tenant on the rental application, known person reasonably believed to be a successor of the tenant as defined in RCW 11.62.005 , and to the deceased tenant at the dwelling unit. The second notice must state that the landlord may sell or dispose of the property on or after a specified date that is at least 45 days after the second notice is mailed if a tenant representative does not claim and remove the property in accordance with this subsection.
(c) The landlord shall turn over possession of the tenant's property to a tenant representative if a written request is made within the applicable time periods after the second notice is mailed, provided the tenant representative: (i) Pays the actual or reasonable costs, whichever is less, of drayage and storage of the property, if applicable; and (ii) gives the landlord an inventory of the property and signs an acknowledgment that he or she has only been given possession and not ownership of the property.
(d) Within the same number of days as required under RCW 59.18.280 , after the removal of the property by the tenant representative, the landlord shall refund any unearned rent and shall give a full and specific statement of the basis for retaining any deposit together with the payment of any refund due the deceased tenant under the terms and conditions of the rental agreement to the tenant representative.
(3)(a) If a tenant representative has not contacted the landlord or removed the deceased tenant's property within the applicable time periods under this section, the landlord may sell or dispose of the deceased tenant's property, except for personal papers and personal photographs, as provided in this subsection.
(i) If the landlord reasonably estimates the fair market value of the stored property to be more than $1,000, the landlord shall arrange to sell the property in a commercially reasonable manner and may dispose of any property that remains unsold in a reasonable manner.
(ii) If the value of the stored property does not meet the threshold provided in (a)(i) of this subsection, the landlord may dispose of the property in a reasonable manner.
(iii) The landlord may apply any income derived from the sale of the property pursuant to this section against any costs of sale and moneys due the landlord, including actual or reasonable costs, whichever is less, of drayage and storage of the deceased tenant's property. Any excess income derived from the sale of such property under this section must be held by the landlord for a period of one year from the date of sale, and if no claim is made for recovery of the excess income before the expiration of that one-year period, the balance must be treated as abandoned property and deposited by the landlord with the department of revenue pursuant to chapter 63.30 RCW.
(b) Personal papers and personal photographs that are not claimed by a tenant representative within 90 days after a sale or other disposition of the deceased tenant's other property shall be either destroyed or held for the benefit of any successor of the deceased tenant as defined in RCW 11.62.005 .
(c) No landlord or employee of a landlord, or his or her family members, may acquire, directly or indirectly, the property sold pursuant to (a)(i) of this subsection or disposed of pursuant to (a)(ii) of this subsection.
(4) Upon learning of the death of the tenant, the landlord may enter the deceased tenant's dwelling unit and immediately dispose of any perishable food, hazardous materials, and garbage found on the premises and turn over animals to a tenant representative or to an animal control officer, humane society, or other individual or organization willing to care for the animals.
(5) Any notices sent by the landlord under this section must include a mailing address, any address used for the receipt of electronic communications, and a telephone number of the landlord.
(6) If a landlord knowingly violates this section, the landlord is liable to the deceased tenant's estate for actual damages. The prevailing party in any action pursuant to this subsection may recover costs and reasonable attorneys' fees.
(7) A landlord who complies with this section is relieved from any liability relating to the deceased tenant's property.