Campus Alert Archive
Cerro Coso

Ridgecrest's M6.4 and M7.1: How a Holiday Earthquake Closed a California Community College

CAearthquakeemergency notificationmedium confidence
Confirmed Threat

On July 4, 2019, an M6.4 earthquake struck near Ridgecrest at 10:33 AM PDT, followed 34 hours later by an M7.1 mainshock at 8:19 PM PDT on July 5. Cerro Coso Community College's Indian Wells Valley campus — sitting near the epicenter — sustained significant structural damage, with most campus buildings deemed unsafe to enter following an inspection by the California Division of the State Architect.

Alerts
4
Response
—
Killed
0
Injured
0
Institution
Cerro Coso Community College
Community College · CA
~5,000 studentsCerro Coso Alert
Confirmed Timeline

Alert Sequence

4 messages in sequence

Some alert texts below are approximate reconstructions from news coverage, not confirmed verbatim transcripts. Reconstructed texts are shown in italic with a dashed border. Verified verbatim texts have a solid border and are marked accordingly.

INITIAL ALERTSMS
Approximate reconstruction217 chars
Cerro Coso Alert: A magnitude 6.4 earthquake has struck near Ridgecrest. The Indian Wells Valley campus is closed pending damage inspection. Stay away from damaged structures. Drop, Cover, Hold On for any aftershocks.

This text has been reconstructed from news coverage and may not reflect the exact original wording.

Pushed within hours of the M6.4 foreshock at 10:33 AM PDT on July 4, 2019, the largest Southern California earthquake in 20 years to that date
July 4 was a federal holiday — campus was minimally occupied, which limited the casualty risk but also delayed building inspections by holiday-staffed agencies
'Drop, Cover, Hold On' is the Cerro Coso ShakeOut standard — repeating the drill language inside the live alert reinforces practiced behavior during the aftershock sequence
UPDATESMS
Approximate reconstruction186 chars
Cerro Coso Alert: A magnitude 7.1 earthquake just struck near Ridgecrest. All campuses CLOSED. Do NOT enter any campus buildings. Move to open ground if outdoors. Aftershocks are likely.

This text has been reconstructed from news coverage and may not reflect the exact original wording.

Pushed within minutes of the M7.1 mainshock at 8:19 PM PDT on July 5, 2019 — the largest California earthquake in 20 years
The capitalized 'CLOSED' and 'Do NOT enter' reflect the elevated stakes after the mainshock: the M6.4 had already weakened structures, and ceiling and light fixtures were now actively dangerous
'Move to open ground if outdoors' addresses Ridgecrest's most common nighttime evacuation scenario — students and staff already outside enjoying the post-July-4 holiday
UPDATEEmail
Approximate reconstructionReconstructed from Cal OES Ridgecrest after-action report and Cerro Coso post-quake communications274 chars
All Cerro Coso Community College campuses remain closed pending damage assessment by the Division of the State Architect. Summer session classes are canceled until further notice. Faculty and staff should not report to campus. We will provide updates as inspections proceed.

This text has been reconstructed from news coverage and may not reflect the exact original wording.

Names the Division of the State Architect (DSA) as the inspecting authority — DSA inspections are the legal threshold for reopening California Community College buildings after major seismic events
Multi-day closure of summer session is itself unusual — community colleges rarely close summer sessions because enrollment is small and revenue is high per seat
Statement that 'faculty and staff should not report to campus' is the operational tell that this was not a 24-hour weather closure but a structural-safety event
UPDATEEmail
Approximate reconstructionReconstructed from Cal OES Ridgecrest AAR and Cerro Coso recovery communications328 chars
Following Division of the State Architect inspections, most Indian Wells Valley campus buildings have been deemed unsafe to enter. Limited operations will resume in cleared spaces. Counseling services and academic flexibility are available for students affected by the earthquakes. Continue to monitor cerrocoso.edu for updates.

This text has been reconstructed from news coverage and may not reflect the exact original wording.

Phrase 'most Indian Wells Valley campus buildings have been deemed unsafe' tracks the language of the official Cal OES Ridgecrest After-Action Report
Acknowledgment of 'limited operations in cleared spaces' is unusually candid for a higher-ed reopening message — it admits partial functionality rather than a clean all-clear
Counseling services framing reflects the unique trauma of an extended earthquake sequence: hundreds of aftershocks continued for weeks across the Indian Wells Valley
Context

Background

Cerro Coso Community College is a small community college serving the Indian Wells Valley and Eastern Sierra region from a main campus in Ridgecrest, California. On the morning of July 4, 2019, an M6.4 earthquake struck near Ridgecrest at 10:33 AM PDT — the largest Southern California earthquake in 20 years to that date. Just over 34 hours later, an M7.1 mainshock at 8:19 PM PDT on July 5 struck on a nearly perpendicular fault. The shaking severely damaged the Cerro Coso Indian Wells Valley campus. The California Office of Emergency Services Ridgecrest After-Action Report documented that 'most campus buildings were deemed unsafe to enter' after Division of the State Architect inspections, with the Learning Center Building specifically cited for damage to ceilings, fire sprinkler interaction, and pendant-light fixtures. The college's annual ShakeOut drills — the same Drop, Cover, Hold On protocol practiced statewide every October — became the basis of the live emergency response. Summer-session classes were canceled, with limited operations resuming over subsequent weeks. The case is significant because it is one of the few US community college closures driven by direct seismic damage in the WEA era and demonstrated the importance of California's DSA inspection regime in reopening damaged campus buildings.
Analysis

Key Findings

The M7.1 mainshock at 8:19 PM PDT on July 5, 2019 was the largest California earthquake in 20 years and damaged most Cerro Coso Indian Wells Valley campus buildings
California's Division of the State Architect inspection regime is the legal threshold for reopening damaged community college buildings — this case is a textbook DSA-triggered closure
The Cerro Coso Learning Center Building was specifically cited in the official Cal OES Ridgecrest after-action report for ceiling, sprinkler, and pendant-light damage
July 4 holiday timing minimized casualty risk on the M6.4 foreshock but also delayed inspections during the aftershock sequence
Cerro Coso's pre-existing ShakeOut drills became the basis of live emergency response — illustrating the value of campus seismic drills in earthquake-prone California
Outcome
Most Indian Wells Valley campus buildings deemed unsafe to enter following inspection. Summer-session classes canceled. The Learning Center Building suffered ceiling and pendant-light damage cited in the state seismic-safety after-action report. Campus partially reopened over subsequent weeks as buildings were cleared.
Provenance

Sources

  1. Report
    2019 Ridgecrest Earthquake After-Action Report (California Office of Emergency Services)
    caloes.ca.gov
  2. Official
    ShakeOut (Cerro Coso Community College)
    cerrocoso.edu
  3. Source
    2019 Ridgecrest earthquakes (Wikipedia)
    en.wikipedia.org
  4. Official
    Update: Magnitude 7.1 Earthquake in Southern California (USGS)
    usgs.gov
  5. Official
    The 2019 Ridgecrest, California Earthquake Sequence – a geonarrative (USGS)
    earthquake.usgs.gov
  6. Report
    Ridgecrest Earthquake Sequence of July 2019 (California Seismic Safety Commission)
    ssc.ca.gov
Tags
earthquakeridgecrestcaliforniacommunity-collegecerro-cosoindian-wells-valleydsa-inspectionshakeoutstructural-damagesummer-session-canceled
Added May 2026Updated May 2026Via ingestion