The Worker Adjustment and Retraining Notification Act ("WARN") requires employers to provide its employees with 60-day notice before the employer (i) orders the closing of a plant involving 50 or more employees during a 30-day period, (ii) lays off 50 to 499 full-time employees constituting at least 33% of the full-time workforce at a single site of employment within a 30-day period, or (iii) lays off 500 or more employees.