Breaking Long-Term Lease due to "Unoccupability"?

[Scott Smith]

I have a long-term, now month-to-month tenant in a property in the District of Columbia. This week we discovered some issues that must be repaired immediately. The repairs will be extensive (more than a month, minimum) and will make it impossible for the tenant to remain in the unit while work is being completed. The tenant has been extraordinarily cooperative and we moved all the tenant's belongings into a storage unit. I offered the opportunity to walk away from the lease with no penalty (usually they have to give advance notice) and the tenant is considering that. On my end, as the landlord, is there anything I can do legally to terminate the lease rather than leaving it to the tenant? My fear is that as work continues, we will discover more and more things that need to be fixed and I don't want the tenant to be in temp housing hoping that this will be a quick fix.

Any thoughts? Never faced this before and I know DC is a very tenant-friendly jurisdiction. Any thoughts would be appreciated!