Unfortunate set of circumstances. My recommendation is to meet with a tax professional. Bring all details you have for this entity; past tax returns, IRS EIN correspondence, etc. The tax professional most likely will want to get a power of attorney so this individual can speak directly and / or correspond directly with the IRS.
*A reminder that posts in a forum such as this do not constitute tax advice.
Also keep in mind the date of replies, as tax law changes.
