I have experienced a mass layoff. Our organization was transparent throughout the process and offered EAP services to those that were laid off and for those that remained. For the employees that were laid off the organization retained an employment service to help with resume writing and job seeking strategies. A project plan had clearly been mapped out and communication occurred throughout the process. My best advice would be to utilize the services being offered, remain transparent throughout the process and be prepared for any questions that may occur. Checking in with supporting staff and management is key as it is just as stressful for those that remain as it is for those that have been laid off.
