This document provides guidance on assessing structural damage to buildings after an earthquake and determining if they are safe to enter. It details signs of light, moderate, and heavy structural damage. Buildings showing heavy damage like collapse, tilting, or obvious instability should not be entered. Those with light damage like broken windows or cracks may be entered to search for occupants. Buildings with moderate damage requiring hasty evacuation like decorative elements falling are only to be entered to locate trapped victims to communicate to rescue teams. Safety precautions around hazards both inside and outside damaged buildings are emphasized.

1. STRUCTURAL DAMAGE ASSESSMENT
Most buildings that have suffered structural damage will show very distinctive
outward signs. Before entering any building, thoroughly check for signs of
possible structural damage.
Buildings are built with straight horizontal and vertical lines. When a building has
suffered structural damage, these straight lines can become distorted. This is a
strong indication that the building’s structural stability has been compromised.
BE FAMILIAR WITH YOUR BUILDING BEFORE HAND, SO YOU WILL
NOTICE CHANGES AFTER AN EARTHQUAKE!
SIGNS OF POSSIBLE STRUCTURAL DAMAGE
A. Horizontal Lines
1. Look for uneven window lines
• Draw an imaginary line across the tops of the windows and see if
they line up.
2. Foundation not level
• Ground around foundation is fractured and uneven
B. Vertical Lines
1. Any leaning
• Look at all sides of the building
• Compare to the buildings next door
2. Entry ways
• Are these paths out of plumb?
C. Large Cracks in the Exterior of the Building
1. Especially around doors and entry ways
2. Foundation cracks
D. Separation Between the Buildings
1. Is it even?
2. Was it there before?
3. Are other buildings in the school similar?
E. LIquefaction
1. Around the foundation area
2. Coming out of openings on the ground
ALWAYS BE AWARE OF POTENTIAL HAZARDS AROUND YOU!

2. F. Overhead Hazards
1. Leaning buildings, walls, and utility poles could fall
2. Overhanging pieces of a building may be loosened by the
quake and fall; such as cornices, decorative work or chimneys
3. Utility wires could be exposed and cause electrocution
G. Ground Level Hazards
1. Sharp objects such as:
• Glass
• Nails
• Broken concrete
• Rebar
2. Slippery or uneven surfaces caused by ground movement and water
leaks
H. Below Grade Hazards
1. Contaminated atmosphere in confined spaces due to smoke or gas
leaks.
• Flammable, toxic or oxygen deficient air
2. Flooding due to water leaks
• Drowning
• Electrocution
3. Debris
DAMAGE CLASSIFICATIONS
Once outward signs of structural damage are examined, buildings should be
classified according to the amount of damage sustained . There are three
classifications of structural damage:
• Light Damage
• Moderate Damage
• Heavy Damage
Only buildings classified as “Light or Moderate Damage” should be entered.
DO NOT ENTER BUILDINGS THAT ARE HEAVILY DAMAGED!
A. Light Damage
1. Superficial damage
• Broken windows
• Fallen or cracked plaster
B. Moderate Damage
1. More extensive damage

3. • Exterior decorative work damaged or fallen
• Large amounts of cracking visible
• Building is not leaning
• Still attached to the foundation
• No other outward signs of structural damage
The PRIMARY MISSION of the team is to attempt to gather as much informaiton
as possible about the location of students and staff inside the building before
entering. Then enter and search for, locate, triage, stabilize and immediately
evacuate the victims to the triage area or reunification site. An aftershock could
turn this moderately damaged building into a heavily damaged building quickly,
so spend as little time in them as possible. Document the location of any heavily
trapped victims and communicate the information to professional rescue teams.
Shut off utilities as needed. Document all actions taken.
C. Heavy Damage
1. Extensive Damage
• Partial or total collapse
• Buildings tilting or off their foundations
• Buildings that are obviously structurally unstable
• DO NOT ENTER HEAVILY DAMAGED BUILDINGS!
The PRIMARY MISSION of the team is to secure the building perimeter and
control access into the building by untrained persons. Shut off utilities if it is safe
to do so. If possible, communicate the location and extent of damage to the fire
department and gather information regarding hazards and victims for rescuers.
Document all actions taken.
From the Marin County
School Emergency Response Training (SERT) Handbook