Dear Customer (name blocked for privacy)
If the lease specifically states that you are not responsible for the repair, maintenance, etc of the washer then the tenants are responsible (the washer is a luxury provided to the by you and something you did not have to leave there for their use) - perhaps they have tenants insurance that would help with the cost of the damage. OR perhaps you have some type of homeowners insurance that you could tap into seeking the deductible from the tenants.
Best of success to everyone,
If my answer has been helpful, please ACCEPT my answer so I get credit for my effort to help you . If I can be of further help, let me know. Appropriate FEEDBACK is appreciated as is a bonus. Thanks ~ Michelle