What to Do After an Earthquake: A Structural Assessment Guide

Earthquake Damage Resource Staff 6 min read Earthquake Damage

What to Do After an Earthquake: A Structural Assessment Guide

Earthquakes strike without warning. In Los Angeles and across Southern California, millions of residents live within miles of active fault lines capable of producing significant seismic events. Knowing what to do in the hours and days after an earthquake can mean the difference between catching hidden structural damage early and facing catastrophic failure later.

This guide walks you through the essential steps to take after an earthquake, with a focus on structural assessment and protecting your property and family.

Immediate Safety Steps After an Earthquake

Before you even think about inspecting your home or building, prioritize personal safety.

In the first few minutes:

  • Check yourself and others for injuries. Administer first aid if needed and call 911 for emergencies.
  • If you smell gas, leave the building immediately and contact your utility provider from a safe distance.
  • Do not use open flames, including candles or lighters, until you have confirmed there are no gas leaks.
  • Stay away from damaged buildings, downed power lines, and cracked roadways.
  • If you are indoors and the structure appears stable, put on hard-soled shoes to protect against broken glass and debris.

Within the first hour:

  • Turn off gas and electricity at the main shutoffs if you suspect damage to utility lines.
  • Check for visible cracks in walls, ceilings, and foundations.
  • Open cabinets carefully, as items may have shifted during shaking.
  • Monitor local emergency broadcasts and follow instructions from authorities.

Conducting a Preliminary Visual Inspection

Once the immediate danger has passed, perform a careful walk-around of your property. You do not need to be a structural engineer to spot warning signs, but you do need to know what to look for.

Exterior warning signs:

  • Cracks in the foundation, especially diagonal or stair-step cracks in masonry
  • Shifted or leaning walls
  • Gaps between the foundation and the structure above
  • Damage to chimneys, including leaning, cracking, or partial collapse
  • Buckled or displaced siding and exterior cladding

Interior warning signs:

  • New cracks in drywall, plaster, or stucco, particularly around door frames and window frames
  • Doors and windows that no longer open or close properly
  • Floors that feel uneven or slopes that were not present before the earthquake
  • Visible separation between walls and ceilings or walls and floors
  • Cracks in tile flooring, which can indicate foundation movement

What cracks mean:

Not all cracks indicate serious structural damage. Hairline cracks in drywall may be cosmetic. However, cracks wider than one-eighth of an inch, diagonal cracks in concrete or masonry, and any cracking accompanied by displacement or shifting should be treated as potentially serious and warrant professional evaluation.

When to Call a Structural or Forensic Engineer

Many homeowners in Los Angeles assume that if their building is still standing, it must be safe. This is a dangerous misconception. Earthquakes can cause hidden damage to load-bearing elements, foundations, and connections that are not visible to the untrained eye.

You should contact a licensed structural engineer or forensic engineer if:

  • You observe any of the serious warning signs listed above
  • Your building was constructed before 1980, when seismic building codes were less stringent
  • You live in a soft-story apartment building, hillside home, or unreinforced masonry structure
  • Your property has a raised foundation or cripple wall system
  • You plan to file an earthquake insurance claim and need documentation

A qualified seismic damage assessment team in Los Angeles can perform a thorough evaluation using visual inspection, measurement tools, and engineering analysis to determine whether your structure is safe to occupy, needs repairs, or requires more extensive intervention.

Understanding the Structural Assessment Process

A professional post-earthquake structural assessment typically follows a multi-step process.

Rapid assessment: This initial evaluation determines whether a building is safe to enter. In major earthquakes, city or county inspectors may perform rapid assessments and tag buildings with green (inspected, no apparent hazard), yellow (restricted use), or red (unsafe) placards.

Detailed engineering assessment: A licensed structural engineer examines the building more thoroughly. This includes checking the foundation, framing connections, shear walls, and lateral force-resisting systems. The engineer may use instruments to measure deflections and check for plumb and level conditions.

Forensic investigation: For insurance claims, legal disputes, or complex damage scenarios, a forensic engineer conducts an in-depth investigation. This may include material testing, analysis of construction documents, and comparison with seismic design standards applicable at the time of construction.

Thorough documentation is critical, whether you plan to file an insurance claim, pursue legal action against a builder, or simply keep records for future reference.

Best practices for documentation:

  • Photograph and video all visible damage before making any repairs. Include wide shots for context and close-ups for detail.
  • Use a ruler or measuring tape in photographs to show the scale of cracks and displacements.
  • Note the date, time, and location of each photograph.
  • Keep a written log of all damage you observe, conversations with inspectors, and any professional assessments.
  • Save copies of all reports, repair estimates, and correspondence with your insurance company.

Protecting Your Property Before Repairs

After an earthquake, your building may be vulnerable to further damage from aftershocks, rain, or settling.

  • Cover broken windows and openings with plywood or heavy plastic sheeting.
  • Place tarps over roof damage to prevent water intrusion.
  • Do not attempt structural repairs yourself. Improper shoring or bracing can make a damaged structure more dangerous.
  • If your building has been yellow- or red-tagged, do not enter without authorization.

Planning for the Next Earthquake

Southern California will experience future earthquakes. Use this event as motivation to prepare.

  • Consult with a structural engineer about retrofitting your home, especially if it has a cripple wall foundation, unreinforced masonry, or soft-story construction.
  • Review and update your earthquake insurance policy.
  • Assemble or refresh your emergency supply kit.
  • Develop a family communication plan for the next seismic event.
  • Secure heavy furniture, water heaters, and appliances to prevent them from toppling during shaking.

Take Action Now

The aftermath of an earthquake is stressful and disorienting. Having a clear plan for structural assessment helps you make informed decisions about your safety and your property. If you are in Los Angeles or anywhere in Southern California and have experienced earthquake damage, do not wait. Early professional assessment can prevent secondary damage, support your insurance claim, and give you peace of mind.

Structural damage does not improve with time. The sooner you act, the better positioned you will be to protect your home, your investment, and your family.