Coyle Disaster Classification System

Everyone knows Murphy's Law: anything that can go wrong will go wrong. What few people know is Coyle's Law: Murphy was an optimist.

Disaster, like beauty, is in the eye of the befallen. We might empathize with people in a disaster, but if it is not happening to us, we are likely to take few lessons from the consequences.

What constitutes a disaster is not the cause but the scope of the event. 9/11 offers the best illustration.

On 9/11 four planes crashed. Taken in reverse order, Flight 93 crashed in a field in Pennsylvania. No structures were damaged, no infrastructure impacted, and no one on the ground died. The scope of this crash was minor. Emergency response and security of the site caused little or no lasting effects on the local economy.

Flight 77 crashed into the Pentagon. Damage to the building was extensive, but work resumed in most of the building almost immediately. The local area was impacted only slightly more than in Pennsylvania.

Flights 11 and 175 crashed into the World Trade Center Towers. Initially, the impacts disrupted only the buildings of the Center. Many people and businesses viewing the scene rather than the impact of the crashes themselves caused the loss of productivity. The local area response did not fail. However, the damage done by the initial crashes paled next to the final consequences. The collapse of the Towers severely impacted the entire neighborhood surrounding the Center and compromised and exceeded by orders of magnitude the available response.

Two planes crashing in a field in Pennsylvania would have been a tragic event. Two planes crashing into the Pentagon, a devastating blow. But two planes crashing into and causing the collapse of the World Trade Center Towers was a disaster.

Man made disasters are difficult to create. Although hoped for, the terrorists of 9/11 could not have foreseen the outcomes of their actions. Had all four planes crashed into fields, the aftermath of 9/11 would have been considerably different and the event would likely have never been labeled a disaster.

In 1908 a meteor exploded over the Siberian tundra. Only one death was reported and some small settlements were affected. Had the same event occurred over the Eastern Seaboard of the US, the disaster would have exceeded the combined destruction of Nagasaki and Hiroshima.

The scale or scope of the damage caused by an event is the first factor in classifying a disaster. A 9.1 earthquake in the deep ocean is unlikely to cause as much damage as a 6.8 located under downtown Los Angeles. The location of the event determines the scope of the damage. Similar events in rural and urban settings will have different amounts of damage. A fire in a barn will probably cause less impact in an area than a fire in a row house in a large city.

Disaster Scale One - Scope

Level 1 Single building 9/11 DC
Level 2 Group of contiguous buildings 9/11 NY initial
Level 3 Neighborhood 9/11 NY post collapse
Level 4 Town or multiple neighborhoods Tornadoes
Level 5 Area - multiple sites over a region Cat 1 or 2 hurricane
Level 6 Region Katrina
Level 7 Country/multiple regions War (?)
Level 8 Multiple countries 12/04 tsunami
Level 9 Hemisphere  
Level 10 Global Dinosaur killing meteor

An argument can be made that 9/11 was a Level 5 disaster but that is beyond the scope of this document.

The second factor in determining if an event is a disaster is persistence. One definition of persistence is the amount of time that occurs from the beginning of an event until it’s cause ceases. An earthquake persists for at most a couple of minutes; a fire, hours; a hurricane, days. A second, more useful definition is the amount of time from the end of an event until a response can be made against its effects.

In most First World countries, the time between the cause of a disaster and a first response is measured in minutes. Almost all Level 4 and lower disasters in the US have little or no persistence. (Many locations may experience persistence during higher level events.)

Persistence is also a function of expectations. When a home fire occurs, many people expect a fire department response in mere minutes. If the expectation is that a response will occur within five minutes and it takes seven, people will note a 40% increase in the response time and ignore that it was only two minutes more.

The response to Hurricane Katrina was perceived to be slow, although persistence was well within historical and planned levels. However, the expectations were not met and the perception was that it took too long.

Persistence expectations have to be rational; No one should expect a response within minutes of the rain stopping in a hurricane or within minutes of an earthquake. The scope of these events/disasters can reach Level 5 or higher, usually far above the available resources of even well prepared local areas.

Disaster Scale Two - Persistence

Level 1 24 hours or less
Level 2 24 to 48 hours
Level 3 Less than 96 hours
Level 4 5 to 9 days
Level 5 10 to 21 days
Level 6 Up to a month
Level 7 2 to 6 months
Level 8 6 months to a year
Level 9 1 to 3 years
Level 10 More than 3 years

The last factor in disaster classification is foreknowledge. A disaster is anticipated, expected or surprising. Foreknowledge is often location dependent also. A volcano appearing in a Mexican field is more surprising than an eruption on Hawaii. An earthquake can be anticipated in California but surprising in New York. There is no foreknowledge in a surprising event. The residents of the Gulf Coast should have expected the Katrina disaster or at least anticipated it.

Disasters can be classified in this way:

Level 11n : Scope = 1 (single building)

Persistence = 1 (day or less)

Foreknowledge = n (none)

An example: the crash of Flight 77 into the Pentagon

Level 63e : Scope = 6 (region)

Persistence = 3 (less than 96 hours)

Foreknowledge = e (expected)

An example: Hurricane Katrina

Preparedness Scale Classification

The purpose of classifying disasters is to assist in preparing for them. Disaster preparedness has two separate but compatible participants. First, those affected by a disaster and second, those whose job it is to respond to one. Each has responsibilities that compliment each other.

Those that are affected by a disaster react based upon the foreknowledge available. For the Gulf Coast residents, hurricanes are both anticipated (historically hurricanes make landfall annually) and expected (forecasts are becoming increasingly accurate). Preparing for a hurricane should be a routine exercise for all residents of that area.

For California residents, earthquakes are also both anticipated (historically the area is quite active) and expected (continuing research shows ongoing movement in the earth below the state). Disaster drills are routine, but preparation needs to be also.

For those charged with responding to disasters, foreknowledge of the expected and anticipated disasters should effect planning and readiness states.

Preparedness Scale One - Scope

Level 1 Single building Family home or local business
Level 2 Group of contiguous buildings Campus, mall, apartment complex
Level 3 Neighborhood First responders
Level 4 Town or multiple neighborhoods Municipality planning
Level 5 Area: multiple sites over a region County planning
Level 6 Region State planning
Level 7 Country/multiple regions National planning
Level 8 Multiple countries Joint plans
Level 9 Hemisphere International agreements
Level 10 Global  

Level 1 and 2 preparedness are the responsibility of those occupying these levels. Level 3 and 4 are the responsibility of the local fire, police and governmental units. Level 5 and 6 are the responsibility of state resources and regional cooperation. Level 7 and 8 are the responsibility of national agreements, cooperation and legislative planning. Level 9 and 10 are the responsibility of everyone.

The second requirement for preparedness is to be aware of how long the potential response will take. If you can determine that for all expected and anticipated events, the response time will be less than one hour, then your plans should encompass everything necessary to survive for that one hour. If you determine that the response time will be up to 72 hours, your plans need to provide for everything you need to survive for that 72 hours.

Preparedness Scale Two - Response

Level 1 Less than 10 minutes
Level 2 Less than 1 hour
Level 3 1 to 3 hours
Level 4 Next day
Level 5 72 hours or less
Level 6 4 to 14 days
Level 7 3 to 4 weeks
Level 8 Month or more
Level 9 Up to 6 months
Level 10 Never

Current disaster preparedness sites (including the Red Cross) have many lists of items homeowners should have in anticipation of disaster. These sites have a single failing: very few people plan in advance for disasters. Part of the problem is a lack of scope.

Planning for a Katrina style disaster is prudent along the Gulf Coast and Eastern seaboard, but not in the Rocky Mountains or Upper Midwest. Planning for an earthquake is rational in California, but not in Maine. Planning or preparing for a Level 4-6 disaster can be expensive and time consuming especially if it is not necessary. However, knowing the types and scope of potential disasters is a part of the planning process. Once the event occurs, the ability to prepare is gone.

If all the people of the Gulf Coast had purchased in advance of Katrina all the supplies recommended, almost all the relief provided would have still been necessary as thousands of homes were destroyed or flooded. The likelihood of any one disaster occurring on a given day is very small. Even expected disasters (like a hurricane) can change location or intensity with no or little warning.

The scope and expected response classify preparedness. Specifying the foreknowledge further refines it.

Level 11a : Scope = 1 (single building)

Response = 1 (less than 10 minutes)

Foreknowledge = a (anticipated)

Example : Having a plan for evacuation in event of a fire

Level 65e : Scope = 6 (region)

Response = 5 (72 hours or less)

Foreknowledge = e (expected)

Example : Preparing for a hurricane landfall – boarding windows, ensuring adequate food, water are available, evacuation if appropriate.

A preparedness plan must address all three types of events as indicated by foreknowledge.

Preparedness Matrix

A preparedness matrix specifies the level of planning necessary to respond to specific events. Every matrix has a Level 1 specification. The second row of the matrix is for the specification of a disaster most likely to occur in the location of the planners. The final row of the matrix is for the worst case scenario disaster.

Level 11n

Level 14e

Level 13a

Level 32n

Level 35e

Level 34a

Level 64n

Level 68e

Level 65a

Note: these are not recommended preparedness levels. Knowledge of the type of disasters a location is reasonably likely to have and the general preparedness levels of the surrounding areas need to be considered.

In the United States, most homeowners and businesses are in areas with a local preparedness of Level 42. That is, multiple neighborhoods in an area can expect a response in less than one hour to a disaster affecting them. Adequate planning can and should consider the preparedness of an area.

What plans and actual supplies will be necessary for a business or family in a disaster will vary. A family with a disabled child will have different requirements than those of a couple without children. A business with single location and a couple of employees will have fewer needs than a large business in several buildings and hundreds of on-site employees.

Can or should a preparedness matrix consider events above Level 7? Only if the expected response to a Level 7nea disaster is less than Level 6. If the disaster is 77 or greater, it is a society disrupter and we exceed the capacity to respond to it. We have to adapt to a changed environment and that is Coyle's Law.


* These items should already be available in personal stock to
last for 7-10 days, if not, they are the priority.

# As much as you can carry/store

Day 1: For events up to 1 week
  • Newspaper
  • Groceries:
    • Tuna, in water (bagged & canned)#
    • peanut butter *
    • ziplock snack bags
    • ziplock double seal gallon plastic bags
    • cereal: cheerios, raisin brans *#
    • trail mix #
  • Medicinal
    • Any prescription, at least 90 days of
    • Aspirin *#
    • Antibiotic ointment *#
    • Imodium #
    • Bar soap *

Day 2: For events up to 1 month
  • Big plastic garbage cans
  • BBQ lighters #
  • Groceries:
    • bleach *
    • 10 lb salt *
    • 10 boxes/cans powdered milk
    • 10 lb wheat flour
  • Batteries: D, AA, AAA *#
  • Walkie talkies, longest range #
  • Blankets
  • Gloves - work, warmth
  • Duct tape #
  • Stick matches

Day 3: For events up to 6 months
  • Sleeping bags
  • Hiking Boots and socks
    Sized for each member of party + one size
    larger & smaller
  • Shortwave 2-way radio *
  • Books
    • Gardening
    • Preserving
    • Herbs and husbandry

Day 4: For events up to 12 months
  • Weapons
    • Compound Bow
    • Additional shafts, tips & tools
    • Knives - hunting/fishing
    • Any .22cal rifles and avail ammo
  • Tools
    • 2 tool boxes EACH with
      • Assorted wrenches, pliers, screw drivers
      • Lino knives w/blades #
      • Full socket sets
    • Hand Axes
    • 3 lb sledgehammers, carpentry hammers
    • Shovels
    • Nails (16d, 8d), galvanized screws #
    • Wireties, assorted #
  • 5 rolls #12 solid copper wire
  • 2 to 3 rolls galvanized chickenwire
  • 6mm or thicker rolls black plastic
  • Fishing line (highest test, hooks #
  • Rolls of cotton jersey fabric, sewing needles, thread #
  • 10 boxes, variety sized Safety pins
  • Seeds

Day 5: Indeterminate time
  • Framed backpacks (each member)
  • 2 large binoculars, 2 small
  • RV and towable trailer
  • Dirt
  • Lumber