Plaque near Eastbourne, New Zealand commemorating the Wahine disaster. A hazard of wind, storm, waves, rocks, a weak ship, or poor human decisions and reactions?
(Copyright Ilan Kelman 2004.)
Considerations in compiling and calculating disaster deaths
A. Definitions
1. Disaster
Books have been written about trying to define "disaster" with no resolution. With regards to disaster deaths, the fundamental practical question is which fatal events might not be considered disasters? An example is fifteen solo snowmobilers dying in fifteen separate avalanches compared to three neighbouring families of five people each dying in the same avalanche. Are they all avalanche disaster fatalities or do we make judgements regarding which are disaster deaths and which are not? Some examples of Disaster Definitions.
2. Event
Consistently defining the spatial and temporal scope of disasters is difficult, with the ultimate conclusion that disasters are not events but are processes. Hazards are sometimes events, but delineating start and stop times for linked hazards can be difficult. For example, for Mount Pinatubo in the Philippines in 1991, the fatal ashfalls had relatively clear start and stop times, but lahars continued killing more than a decade after. Is each ashfall and each lahar a separate hazard event or are they all part of the 1991 Mount Pinatubo eruption as a hazard event or long-term volcanic hazard process? Similarly, delineating geographical boundaries for a hazard's spatial extent can be inconsistent. When a single tropical cyclone (a hazard event) hits multiple countries, some databases list it as multiple disasters, one per country.
3. Hazard categories
Hazard categories frequently overlap and are not always consistently defined. Tropical cyclones in Bangladesh are sometimes listed as wind storms, even though most studies show that most of the deaths are water-related, from drowning in storm surge or freshwater flooding. That is, the storm might be considered to be more wind-related but the disaster deaths tend to be more flood-related (and different types of floods). Similarly, deaths in earthquake-induced landslides deaths have been considered either earthquake deaths or landslide deaths depending on the author. Tsunamis have many origins, yet tsunami-related deaths are often pooled as a single category of tsunami deaths. Others might be ambiguous regarding whether or not they always belong as disaster deaths such as:
- Macrobiological hazards.
- Unusual Floods and Drownings.
- Oesterhelweg, L. and K. Püschel. 2008. "'Death may come on like a stroke of lightening...': Phenomenological and morphological aspects of fatalities caused by manure gas". International Journal of Legal Medicine, vol. 122, pp. 101-107.
4. Causality
Why do disaster deaths happen? Definitionally, it is not because of the hazards--events or processes--but because of vulnerabilities. Vulnerability is the long-term process of social values, behaviours, actions, values, and decisions, which mean that some people cannot deal with potential hazards, so they become harmed and disasters occur. While the physical forces and energies of hazard parameters lead to medical problems which can induce death, the fundamental cause is that the people could not avoid those hazard parameters. This cause of death is vulnerability, not the hazard.
B. Data
5. Skewed statistics
Hazards and events, small and large, can skew statistics in three ways. First, a single large event could radically alter long-term trends. The literature does not yet report any verifiable human deaths from a meteorite strike in recorded history, but a single large event could dwarf the total death toll from all disasters over the past millennium. Second, underreported small events have less influence on overall statistics than they should have, even though their cumulative impact might be far greater than the events garnering attention, which is termed "invisible disasters" problem. Third, hazard and vulnerability baselines are always changing, so establishing trends is not as simple as tracking numbers over time.
6. Counting
Counting fatalities can be inconsistent. After Hurricane Katrina hit the USA in 2005, deaths amongst evacuees in Harris County, Texas were compiled with a pregnant woman listed as two separate fatalities. Disaster death compilations vary about whether or not they include homicides, suicides, and vehicle crashes within the tally of disaster-related deaths. A similar discrepancy arises from vehicle crashes related to wildfire smoke or evacuees falling asleep while driving.
7. Prevented deaths
Deaths can be prevented due to a hazard, such as fewer vehicle crashes if people do not drive in a blizzard or a storm. Should disaster deaths researchers calculate background rates of all "normal" deaths and add or subtract any differences following a disaster? Or should the focus be identifying only who is clearly killed in a disaster rather than considering overall rates? As well, some studies have noted that in the months and years following a disaster, the background rate of deaths decreases, because the disaster killed the most vulnerable members of the population who would have soon succumbed to "normal" death causes without the disaster. This observation is termed "the harvesting effect" and is particularly notable for heat waves and cold waves.
8. Non-immediate deaths
Non-immediate deaths from disasters can occur months or years after a hazard. A person might have long-term physical injuries or mental health impacts, eventually leading to death. This point connects to the question regarding when a disaster or hazard stops.
C. People's behaviour
9. Risk judgements
Judging and misjudging risks, including possible consequences, occurs prior to and during hazards, often influencing whether or not an individual is killed or survives. Judgements might or might not be influenced by different levels of information, from formal education over years to warnings being issued now. Understanding how and why these risk judgements occur is not straightforward, especially if the individual is killed.
10. Risk-related actions
Once a judgment is made regarding risks, action (or inaction) will be taken. The form of risk-taking or risk-avoiding (in)actions influences fatalities. Actions might or might not be influenced by different levels of information, from formal education over years to warnings being issued now. Different people have different options available, such as the difference between climbing a volcano for photography or gas samples compared to poverty forcing people to live in informal settlements on a volcano's slope. Specific (in)actions do not necessarily follow specific risk judgements and determining why (in)actions were taken is not easy, especially if the individual is killed.
11. Rescue and response
Search, rescue, and medical efforts--or lack thereof--frequently make the difference between survival and fatality. Where resources are put into emergency response and medical treatment (as is appropriate) while vulnerability reduction is neglected (which is not appropriate), disaster death tallies might not reflect the chronic conditions in which people live, always leaving them at risk. Prevention being better than cure does not mean to diminish the role of cures, but successful cure can lead to views that prevention is less important.
Grouping D: Data analysis
12. Proportional and absolute numbers
Both numbers of deaths and rates of deaths are important to calculate. Proportionality of fatalities within a population has different manners of calculation, such as death rates within the entire population and death rates within subgroups, whether defined through demographic characteristics or other categorisations.
13. Each factor's importance
The relative importance of factors listed here can vary, especially the sensitivity of results to choices made during the analysis. Conducting multiple analyses simultaneously would help to check the results and to determine their sensitivities to choices made.
14. Analysis scale
Comparing disaster death analyses at different spatial and temporal scales could provide insights into what the data can and cannot explain.

How useful is the past as a guide to the future? (near Sendai, Japan).
(Copyright Ilan Kelman 2014.)
Case study: Astronomical hazards
Causes and circumstances of deaths from astronomical phenomena are not well-studied, providing an interesting research area into deaths and potential deaths from NEO (Near-Earth Objects such as comets and asteroids) impacts along with geomagnetic storms and other forms of space weather. Numerous websites cite cases of meteorite-related casualties, but none could be verified until 15 February 2013. In the morning local time, as caught by numerous videos and photos, a meteorite burned through the atmosphere over the Chelyabinsk region, Russia. The shockwave shattered glass in thousands of buildings, injured over 1,200 people, and collapsed a factory roof. It appears as if no large fragments fell in populated areas and that no one was hit by any meteorite fragments.
The casualties, it seems, were all injuries with only a handful being serious, so no fatalities, similar to other cases. The negative, though, is hard to prove: how could we be certain that no one has died? The best feasible statement might be that no death in human history has yet been verifiably attributed to space objects.
NASA around 2000 stated on one of their websites that "It is a fact that there is no record in modern times of any person being killed by a meteorite". Papers give other potential examples, none of which are confirmed. Pickering (1919) quotes the Bible for one example of deaths and also suggests one story of a man killed by a meteorite in India in 1827. Yamamoto (1928) describes a report of a 3-year-old girl in Japan being hit by a meteorite and suffering minor injuries. Yau et al. (1994) and International Comet Quarterly list several examples throughout history where meteorites are stated as having killed or injured people. On 9 February 2016, BBC reported a potential meteorite death.
With reference to the 30 June 1908 Tunguska explosion in Siberia, Cohen (2008) writes "Many Evenki, a tent-dwelling nomadic people indigenous to the area, told of animals, their homes and even fellow tribespeople being hurled into the air by a shock wave. An unfortunate few were incinerated". It is unclear what evidence exists to support that contention or if it is part of the local folklore. As well, an ongoing debate surrounds the date of the Kaali meteorite strike on Saaremaa, Estonia within the last several thousand years and the extent of human inhabitation at the time. If the island was inhabited during the strike, fatalities would have been likely, but almost impossible to prove or disprove.
Examples of Kaali meteorite strike references (210 kb in Word).

The Kaali meteorite crater on the island of Saaremaa, Estonia, created within the last several thousand years. Did the impact kill anyone?
(Copyright Ilan Kelman 2008.)
Chapman (2004; see also Chapman and Morrison, 1994) estimates the annual number of deaths internationally from NEO impacts as averaging between 300 and 3,000, based on the annual probability of different sized impacts, the time available to respond to specific threats, and the predicted consequences of events. These results are naturally dominated by low-probability high-consequence events meaning that year-to-year deaths are usually zero. Plenty of literature (e.g Kuypers et al., 1999 and Xie et al., 2005) exists on mass extinctions due to astronomical phenomena before human beings existed.
The threat to Earth from NEOs has led to monitoring and warning programmes. Several search programmes exist in Europe, the USA, and Japan (Fulchignoni and Barucci, 2005; Thuillot et al., 2005). Plenty of international discussion has occurred regarding how to avert or prepare for a collision once a threat has been identified, but more operational planning and testing of countermeasures is needed (Carusi et al., 2005).
Tsunamis could be caused by asteroid or comet impacts. Kharif and Pelinovsky (2005) report that the most recent known ocean impact occurred approximately 2.15 million years ago, although traces from more recent, smaller events might have vanished. It is possible that no human fatalities have yet resulted from a space-impact-related tsunami.
An individual's characteristics leading to fatalities from astronomical phenomena can include belief systems. Many cultures have interpreted comets and bright meteors as portending calamity (Brown, 1973), likely leading to suicides. In 1997, one sect saw Comet Hale-Bopp's arrival as an opportunity to board a spaceship to the Promised Planet and 39 people committed suicide in a group (Mancinelli et al., 2002). As well, fatalities from heart attacks might have occurred due to meteorite strikes or sudden meteor flashes. Individual characteristics which increase or decrease the potential for astronomical hazard-related suicide or heart attack could be a research area.
The physical mechanism of most space impact deaths would be crushing or physical trauma by the object if it lands, burning from an atmospheric explosion, trauma due to physical forces from the pressure wave or shock wave, or similar mechanisms to earthquakes (including tsunamis, if they occur) as the impact waves radiate outwards. An object could potentially skim the atmosphere without a direct impact, resulting in a regional superfire and/or pressure wave catastrophe along with the consequences of accompanying changes in atmospheric chemistry leading to acid rain and ozone layer destruction (e.g. Munich Re, 2001). Therefore, the principal space object hazard characteristics related to fatalities would be momentum (the product of mass and velocity) and trajectory (which would be included within the velocity vector).
Extraterrestrial radiation is an astronomical phenomenon related to cancer fatalities, particularly solar radiation exposure exacerbated by the ozone hole as a factor in skin cancer rates (e.g. Green et al., 1999; Oikarinen and Raitio, 2000). These studies also discuss an individual's characteristics which could increase their vulnerability to skin cancer. Other radiation phenomena such as giant flares from other stars--for instance, the 27 December 2004 event reported by Palmer et al. (2005)--lead to the scientists commenting in the media that similar events within several light years of Earth could cause a mass extinction.
Significant scope exists for further research into the causes and circumstances of fatalities from the environmental hazard of astronomical phenomena.
Brown, P.L. 1973. Comets, Meteorites and Men. Robert Hale and Co., London, U.K.
Carusi, A., E. Perozzi, and H. Scholl. 2005. "The Near Earth Objects: possible impactors of the Earth. Mitigation strategy". Comptes Rendus Physique, vol. 6, no. 3, pp. 367-374.
Chapman, C.R. 2004. "The hazard of near-Earth asteroid impacts on earth". Earth and Planetary Science Letters, vol. 222, issue 1, pp. 1-15.
Chapman, C.R. and D. Morrison. 1994. "Impacts on the Earth by asteroids and comets: assessing the hazard". Nature, vol. 367, pp. 33-40.
Fulchignoni, M. and M.A. Barucci. 2005. "The Near Earth Objects: possible impactors of the Earth. NEO Impact Consequences and Hazards". Comptes Rendus Physique, vol. 6, no. 3, pp. 283-289.
Green A, D. Whiteman, C. Frost, and D. Battistutta. 1999. "Sun Exposure, Skin Cancers and Related Skin Conditions". Journal of Epidemiology, vol. 9(no. 6 Supplement), pp. S7-S13.
Kharif, C. and E. Pelinovsky. 2005. "The Near Earth Objects: possible impactors of the Earth. Asteroid impact tsunamis". Comptes Rendus Physique, vol. 6, no. 3, pp. 361-366.
Kuypers, M.M.M., R.D. Pancost, and J.S. Sinninghe Damste. 1999. "A large and abrupt fall in atmospheric CO2 concentration during Cretaceous times". Nature, vol. 399, pp. 342-345.
Mancinelli, I., A. Comparelli, P. Girardi, and R. Tatarelli. 2002. "Mass Suicide: Historical and Psychodynamic Considerations". Suicide and Life-Threatening Behavior, vol. 32, no. 1, pp. 91-100.
Munich Re. 2001. Topics – Annual review: Natural catastrophes 2001. Munich Re Group, Munich, Germany.
Oikarinen, A. and A. Raitio. 2000. "Melanoma and other skin cancers in circumpolar areas". International Journal of Circumpolar Health, vol. 59, no. 1, pp. 52-6.
Palmer, D.M., S. Barthelmy, N. Gehrels, R.M. Kippen, T. Cayton, C. Kouveliotou, D. Eichler, R.A.M.J. Wijers, P.M. Woods, J. Granot, Y.E. Lyubarsky, E. Ramirez-Ruiz, L. Barbier, M. Chester, J. Cummings, E.E. Fenimore, M.H. Finger, B.M. Gaensler, D. Hullinger, H. Krimm, C.B. Markwardt, J.A. Nousek, A. Parsons, S. Patel, T. Sakamoto, G. Sato, M. Suzuki, and J. Tueller. 2005. "A giant gamma-ray flare from the magnetar SGR 1806-20". Nature, vol. 434, pp. 1107-1109.
Pickering, W.H. 1919. "Meteorites and Meteors". Popular Astronomy, vol. 27, no. 4, pp. 203-209.
Thuillot, W., J. Vaubaillon, H. Scholl, F. Colas, P. Rocher, M. Birlan, and J.-E. Arlot. 2005. "The Near Earth Objects: possible impactors of the Earth. Relevance of the NEO dedicated observing programs". Comptes Rendus Physique, vol. 6, no. 3, pp. 327-335.
Xie, S., R.D. Pancost, H. Yin, H. Wang, and R.P. Evershed. 2005. "Two episodes of microbial change coupled with Permo/Triassic faunal mass extinction." Nature, vol. 434, 494-497.
Yamamoto, I. 1928. "Probability of Injury by a Meteorite". Popular Astronomy, vol. 36, no. 3, pp. 207-208.
Yau, K., P. Weissman, and D. Yeomans. 1994. "Meteorite falls in China and some related human casualty events". Meteoritics, vol. 29, no. 6, pp. 864–871.

Are the sun's rays an astronomical environmental hazard?
Sunset on Inis Oirr, Aran Islands, Ireland.
(Copyright Ilan Kelman 1997.)
Roadside cross memorial for a victim of this low-water crossing on Upolu, Samoa.
The story is that, after heavy rainfall producing flash flooding, the river was overflowing this crossing, a van tried to cross it, and the vehicle was swept away. Several people in the van escaped, but one died.
(Copyright Ilan Kelman 2004.)