Getting references after a company closes after 15 years as an administrative assistant

My manager was laid off too and I am unsure who to use as a reference. There are 15 people counting on me, so I am trying to be careful. A colleague offered to vouch for me. Who did you use?

Thanks for writing this out. I went through something close to it last year, and it got easier once I kept a simple log of every call and form.