Below are several WARN Act compliance considerations discussed during a recent Varnum webinar. Which Employers Are Covered by the WARN Act? An employer’s obligations under the WARN Act are triggered by events that constitute a “plant closing” or “mass layoff” as defined by the Act. There is much confusion about whether and when the WARN Act applies to “temporary” workers. Although limited exceptions may permit less than 60 days’ notice, employers must still provide as much notice as practicable.