---
pretty_name: Largest US layoff events since 1988 - WARN Act notices clustered by employer
license: cc-by-4.0
language:
  - en
task_categories:
  - tabular-classification
tags:
  - layoffs
  - largest-layoffs
  - biggest-layoffs
  - layoff-events
  - mass-layoffs
  - warn-act
  - warn-notices
  - entity-resolution
  - labor-market
  - corporate-events
  - public-records
  - government-data
  - alternative-data
  - united-states
  - daily-updated
  - tabular
size_categories:
  - 1K<n<10K
configs:
  - config_name: default
    data_files:
      - split: train
        path: data/largest_layoff_events.csv
---

# The 1,000 largest US layoff events on record under the WARN Act, 1988-2026

**Rebuilt 2026-09-16. Largest on file: United Airlines, 2020-07-01 to 2020-10-01 — 45,360
workers across 25 notices in 14 state(s). The table's floor is
846 workers; 560 of the 1,000 events span more than one notice and
381 span more than one state.**

A state WARN portal lists one row per site per notice. "What was the biggest layoff?" is an
employer-level question, and answering it takes three steps no portal performs: 48 agencies'
notices normalized into one schema daily, an employer's many spellings resolved to one name
(Boeing files under 22 of them, typos included), and its rolling per-site notices clustered into
one event. This dataset is the result, top 1,000 by reported workers, rebuilt daily.

![Largest layoff events by reported workers](chart.svg)

## Read this before quoting a rank

* **Coverage is uneven before ~2020.** The archive reaches back to 1988 only for the states
  whose portals kept history (Illinois and Oregon among them); most states begin between 2010
  and 2023. `states_covered_in_year` says how many states the archive holds for the event's
  year — an early-year rank is a rank among the states we hold, not the country.
* **An event is one employer's notices with no gap longer than 45 days between consecutive
  notice dates, and no longer than 183 days end to end.** A rolling programme is one event;
  a later round, or the seventh month of a continuous programme, is a separate event.
* **`workers_reported` can overstate a rolling programme.** Exact duplicate rows (same state,
  location, count, notice date and effective date) are dropped (`duplicates_dropped`), but successive
  notices for the same site are summed because a portal does not say whether the second is
  cumulative. `sites` is the conservative companion figure.
* **`single_notice=true` means the whole event is one portal row.** It is only as reliable as
  that row; check it at the source before repeating it.
* Employer names are resolved by [`alias_merge.py`](https://github.com/APVentureEngine/warn-act-notices/blob/main/product/alias_merge.py)
  (token signature + purity-guarded prefix absorption); the resolver ships in this repo. It
  merges spellings, not corporate parents: subsidiaries filing under their own names are their
  own employers.
* The current year is a running total; `event_open=true` marks events that may still grow.

## Top 20 right now

| # | employer | period | workers | notices | states |
|---|---|---|---|---|---|
| 1 | United Airlines | 2020-07-01 to 2020-10-01 | 45,360 | 25 | CA;CO;FL;HI;IL;IN;MN;NJ;NV;NY;OH;PA;VA;WA |
| 2 | OS Restaurant | 2020-03-15 to 2020-05-15 | 38,688 | 128 | CA;FL;IN;KS;MD;MO;NC;NY;OH;PA;SC;TN |
| 3 | Northwest Airlines | 1998-08-11 to 1998-08-11 | 27,500 | 1 | OR |
| 4 | usi services group | 2020-03-01 to 2020-03-01 | 23,695 | 1 | NJ |
| 5 | United Airlines | 2002-12-30 to 2002-12-30 | 18,636 | 2 | IL |
| 6 | Walt Disney Parks and Resorts U.S | 2020-09-30 to 2020-11-18 | 17,780 | 19 | CA;FL |
| 7 | Tend Exchange Subsidiary LLC and Delaware Tender Staffing | 2025-05-20 to 2025-05-20 | 16,132 | 1 | CA |
| 8 | Delaware North | 2020-06-04 to 2020-07-28 | 14,210 | 32 | CA;CO;FL;MD;MI;MO;NY;OH;OK;SC;TN;VA;WI |
| 9 | David's Bridal | 2023-04-14 to 2023-08-11 | 12,964 | 78 | AK;AL;CA;CO;CT;GA;MA;ME;MN;MO;NC;NE;NJ;NM;NV;NY;OH;OR;TN;TX;WA;WI |
| 10 | Yellow | 2023-07-30 to 2023-08-18 | 12,146 | 73 | AL;AZ;CA;CO;DC;FL;ID;IL;IN;KS;ME;MI;MN;NC;ND;NM;NV;NY;OH;TX;VA;WA;WI |
| 11 | HMSHost | 2020-03-20 to 2020-08-18 | 12,080 | 78 | AK;CA;CO;DE;FL;HI;IL;MI;MO;NC;NJ;NV;NY;OH;OR;TN;WA |
| 12 | Ideal US Talent Systems Worker OpCo | 2026-05-04 to 2026-05-29 | 11,973 | 3 | GA;IL;RI |
| 13 | Cinemark | 2020-03-26 to 2020-04-17 | 11,297 | 140 | AZ;CA;CT;ID;IL;IN;KS;MD;MI;MT;NC;NV;NY;OH;PA;SC;TN;TX;UT;VA;WA;WI |
| 14 | Tesla | 2020-05-12 to 2020-05-12 | 11,239 | 2 | CA |
| 15 | Marriott Hotel Services | 2020-03-13 to 2020-06-11 | 10,853 | 32 | CA;CT;FL;NY;PA;TN;VA;WA |
| 16 | Great Atlantic and Pacific Tea | 2015-07-01 to 2015-11-12 | 10,039 | 102 | CT;NJ;PA |
| 17 | American Airlines | 2020-07-15 to 2020-07-29 | 10,013 | 15 | CA;CO;IL;NC;NY;OK;WA |
| 18 | Aramark | 2020-07-31 to 2020-11-18 | 9,977 | 50 | CA;CO;DC;DE;FL;IL;IN;MD;MI;MO;NJ;NV;NY;OH;OK;PA;TX;WA;WI |
| 19 | Hyatt Regency | 2020-03-21 to 2020-07-08 | 9,477 | 49 | CA;CO;DC;FL;HI;IL;MD;MN;NY;OH;OR;TX;VA;WI |
| 20 | Boeing | 2020-06-08 to 2020-10-19 | 8,783 | 12 | CA;WA |

## Columns

| column | meaning |
|---|---|
| `rank` | position by `workers_reported` (ties: earlier start first) |
| `employer` | most frequent canonical spelling inside the event |
| `event_start`, `event_end`, `year` | first and last notice date; `year` is the start year |
| `workers_reported` | sum of `employees_affected` over the event's de-duplicated notices |
| `notices`, `notices_with_worker_count` | notices in the event; how many carried a count |
| `sites` | distinct state + location pairs |
| `states`, `states_count` | semicolon-separated state codes |
| `largest_single_notice`, `largest_notice_state`, `largest_notice_location` | the biggest single filing inside the event |
| `notice_types` | distinct raw `notice_type` strings, as the portals wrote them |
| `single_notice` | `true` when the event is a single filing |
| `event_open` | `true` when the last notice is within 45 days of the rebuild date |
| `duplicates_dropped` | exact duplicate portal rows removed before summing |
| `states_covered_in_year` | states with any notice in the archive for `year` |
| `employer_page` | the employer's history page on the site, when one exists |
| `notice_ids` | semicolon-separated ids joining to the flagship notices CSV |

## Where the rows come from

The free, CC BY 4.0 [normalized WARN archive](https://huggingface.co/datasets/APProjects/us-warn-act-layoffs-notices-daily) rebuilt daily from 48 state portals
([site](https://approjects-warn-act-notices.static.hf.space), [GitHub](https://github.com/APVentureEngine/warn-act-notices)). Related cuts of the same archive: [employers filing in
several states](https://huggingface.co/datasets/APProjects/us-multi-state-layoffs-employers-warn-act) and [layoffs per capita by state](https://huggingface.co/datasets/APProjects/us-layoffs-per-capita-by-state-warn-act).

Get told the day an employer on your list files, in any of the 48 states: [free 30-day
watch](https://approj.gumroad.com/l/warn-free-watch) (no card) or [WARN Watch, $49/year](https://approj.gumroad.com/l/warn-watch) for a list of up to 500
employers.

*Automated publisher (APProjects). Not affiliated with any government agency. Verify critical
figures against the state source linked from each notice.*