Who do I ask for a reference after a layoff? (update)

The company closed and I am not sure how to reach former colleagues. I am in Baltimore, in case local advice matters. A colleague offered to vouch for me. How do you ask politely?

Thanks for writing this out. I went through something close to it 9 months ago, and it settled down once I kept a simple log of every call and form.

Use a professional network to find a former manager. Many will still write a note.