What it is
Federal WARN reaches employers with 100+ employees in covered layoff events: 60 days of notice to employees, the state dislocated-worker unit, and the local official. Mini-WARN states push the thresholds lower and add remedies: California (75 employees counting part-time, $500/day civil penalty, Labor Commissioner route), Washington (50 employees, notice to the state plus employees/union), New Jersey (50 employees, plus severance near one month per year of service), New York (90 days at 50 employees), Illinois (75 full-time, plus mandated severance near 4 weeks per year of service). Colorado runs an agency-notice regime on federal thresholds.
What to do about it: Ask in writing for the notice date, the site address, and the number of employees affected. The per-day damages math is built from the notice date, not from the day you were told.
Plain-language description of US practice, not legal, tax, or financial advice. The paired guide carries the citations, dates, and thresholds; the state pages carry the local windows.