It depends on if the employer is asking for reorganization or is just trying to cancel all outstanding debt. The employee’s salary is considered a debt owed by the company.
In a reorganization the employee may be asked to work for a lower salary with the promise that past due salary will be paid later. For the employer that shuts its doors and goes into bankruptcy, the employees may stand with the rest of the creditors who are owed money by the employer.
Bankruptcy trustees are usually very cognizant about paying employees for the work already performed. Issues of vacation earned and other employee benefits can take some time to resolve. If your employer shuts its doors, immediately apply for unemployment benefits to tide you over until you can obtain another job.