References when my manager was laid off too

The company closed and I am not sure how to reach former colleagues. I have read a lot of threads here and could not find my exact situation. HR only confirms titles and dates. Is a client acceptable?

Thanks for writing this out. I went through something close to it last year, 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.