Employment
As some workers were paid for 60 days after they were told to leave, the layoffs did not trigger the Federal WARN act, as a subset of the workers laid off were technically still employed.
http://www.ca6.uscourts.gov/opinions.pdf/16a0002p-06.pdf
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.