Have your sons apply for unemployment. Surf for a copy of the WARN Act and read it carefully. Check your state's labor laws and look for "Plant Closing." Depending on how many employees were affected by the plant closing, your state must offer retraining, unemployment compensation and worker relocation services. If your sons' company closed because of "foreign imports," they could also be eligible for federal government compensation and job relocation services. Your area unemployment office should be able to help you determine all of this. Have your sons ask to speak to an unemployment counselor when they sign up for their unemployment.
As for the company closing under bankruptcy, the following is paid first and in this order:
Government taxes;
Lawyers;
Secured debt;
Unsecured debt;
Payroll.
Unfortunately, payroll is last, which means that if there is no money left, no one gets paid -- the law really should be changed to put payroll higher on the list, but no one has done it yet. As an aside, the reason is probably because most politicians are x-lawyers and they like being second on the list while there is possibly still some money there!