In the case of Citicorp Industrial Credit, Inc. v. Brock, Secretary of Labor (1986), the United States Supreme Court ruled that an employer's obligation under the Worker Adjustment and Retraining Notification Act (WARN) to provide 60 days' notice before a plant closing or mass layoff is not triggered until it becomes reasonably foreseeable that such events will occur within 60 days. The court held that this requirement does not apply when there is only a possibility or even probability of such events occurring more than 60 days in advance. This decision clarified how employers should interpret their obligations under WARN and provided guidance on what constitutes "reasonable foreseeability" for purposes of triggering these requirements.

In the dissenting opinion for CITICORP INDUSTRIAL CREDIT, INC. v. BROCK, Justice O'Connor disagreed with the majority's interpretation of the Worker Adjustment and Retraining Notification Act (WARN). She argued that Congress intended WARN to apply only when a single employer was responsible for mass layoffs or plant closings. In this case, Citicorp acted as an agent in leasing employees from other companies; it did not directly employ them itself. Therefore, she contended that Citicorp should not be held liable under WARN because it was not their direct employer. Furthermore, she expressed concern about potential negative consequences of expanding WARN's scope beyond what Congress had intended: namely increased costs and legal uncertainty for businesses engaging in complex transactions involving leased employees.