Contributing factors to slip, trip, and fall fatalities at surface coal and 

metal/nonmetal mines 

Mahiyar F. Nasarwanji 

National Institute for Occupational Safety and Health 

Pittsburgh Mining Research Division 

626 Cochrans Mill Road 

Pittsburgh, PA 15236 U.S.A. 

Previous work has been done in the mining industry to identify contributing factors for injuries based 

on MSHA reports of fatalities and non-fatal injuries. Although slips, trips, and falls account for a large 

proportion of fatalities and non-fatal injuries, the contributing factors associated with these incidents have 

not been adequately documented in the mining industry. To this end, publically available MSHA reports 

describing fatalities were coded to identify job categories, activities, causal factors, and contributing factors 

for slip, trip, and fall fatalities at surface mining facilities. Laborer, equipment operator, 

mechanic/maintenance man, and supervisor/management/trainer were the job categories associated with a 

large proportion of fatalities. Maintenance and repair has been shown to be a hazardous task, and it was 

also found to result in slips, trips, and falls fatalities. In addition, installation, construction, and dismantling 

were common tasks at the time of the incidents. The cause of most fatalities involved a fall from height for 

both the coal and metal/nonmetal sectors, with falling through an opening, failure of the ground/equipment, 

or being ejected from/thrown off of equipment being secondary causes. The most common contributing 

factor was the lack of fall protection or inappropriate use of fall protection. Inadequate barriers, equipmentrelated factors, and a lack of adequate operating procedure were also identified as contributing factors. To 

prevent slip, trip, and fall fatalities, it is recommended that (1) special attention be placed on maintenance, 

repair, construction, and dismantling activities, (2) appropriate and adequate barriers are installed when 

needed to prevent inadvertent access, (3) equipment is regularly inspected and maintained, and (4) 

employees are provided appropriate safety equipment, safe working procedures are established and 

followed, and adequate training is provided. 

INTRODUCTION 

Mining is a hazardous occupation leading to 

approximately 10,500 non-fatal injuries a year (Mine Safety 

and Health Administration, 2003-2012). Approximately 21% 

of these non-fatal injuries can be attributed to slips and falls. 

The large proportion of injuries associated with slips and falls 

also plague other industries such as construction, healthcare, 

and food services (Bell, Collins, Dalsey, & Virginia, 2010; 

Courtney, Sorock, Manning, Collins, & Holbein-Jenny, 2001; 

Lipscomb, Glazner, Bondy, Guarini, & Lezotte, 2006). 

The Mine Safety and Health Administration (MSHA) 

provides a detailed description of all fatalities that occur at 

mine sites in a public fatal accident investigation report 

(referred to as fatal report from now on) 

(http://www.msha.gov/data-reports/fatality-reports). These 

fatal reports provide detailed information and are often used to 

identify common citations and as case examples in training. 

Importantly, the reports also provide additional information 

including remedial actions that could prevent further incidents. 

In 2005, Chi, Chang, & Ting (2005) systematically 

evaluated fall fatalities in the construction industry and 

identified a number of contributing factors and preventative 

measures including barriers and restraint systems that could 

help improve health and safety in the construction industry. 

Similarly, work has been done in the mining industry to 

identify contributing factors for injuries based on MSHA 

reports of the fatality (Drury, Porter, & Dempsey, 2012; 

Reardon, Heberger, & Dempsey, 2014). However, slips, trips, 

and falls were not the primary focus of those investigations. 

The aim of this study was to identify the causes of slip, trip, 

and fall fatalities in the mining industry, and document 

contributing factors that if eliminated may have prevented the 

fatalities. 

METHODS 

Case selection 

The detailed fatal reports published by MSHA were used 

for this analysis. The fatal reports can be categorized based on 

general incident type and provide a description of the incident, 

any investigation that was carried out, the root cause of the 

incident, and citations served. 

A preliminary review of both coal and metal/nonmetal 

fatal reports for a 10-year period from 2003-2012 was 

conducted by two reviewers independently to identify if the 

event entailed a slip, trip, or fall and occurred at a surface 

operation (i.e., a non-underground mining operation). A list of 

potential fatal reports was compiled for further classification 

and coding after discrepancies in the potential list were 

resolved though discussion. Forty-seven of 242 fatal reports 

from the metal/nonmetal sector and 20 out of 299 from the 

coal sector over the 10-year period of interest entailed a slip, 

trip, or fall event. 

Classification and coding 

Preliminary coding was carried out on 20 fatal reports by 

two coders to develop and refine the coding scheme. The 

Proceedings of the Human Factors and Ergonomics Society 2016 Annual Meeting 1666
categories of interest included the job category of the 

individual involved, activity at the time of the incident, the 

cause of injury, and the contributing factors. 

Job categories were coded based on what was specified in 

the fatal report, and terms commonly used by MSHA for 

coding fatalities and non-fatal injuries were used as 

descriptors. A list of activities at the time of the incident was 

created based on the preliminary coding and included 

categories such as routine maintenance and repair, 

installation/construction/dismantling of new/old equipment or 

structures, daily operations (activities performed as part of 

regular operation of a mine, such as operating equipment), 

housekeeping, inspection, and supervising. 

To code the cause of the fatality, Chi et al. (2005) used 

the US Department of Labor event categories similar to those 

used by MSHA. One shortcoming of this approach was that it 

is not clear if a fall was from a height (i.e., if the surface from 

which the fall occurred was above the surface on which the 

victim landed). To help alleviate this issue, if the location 

from which the individual fell was known, it was specified in 

the coding or the incident was coded as a fall from height or a 

fall to same level. The primary cause of the fatality was often 

stated in the fatal reports; however, the exact surface of origin 

and events leading to the fatality or secondary causes were 

often unclear. For example, although the fatal reports may 

indicate that the individual fell from a height, it was unclear 

where exactly the individual was standing or what caused the 

fall (e.g., a slip or unexpected movement). 

For each incident, it was assumed that there was at least 

one contributing factor that if eliminated/rectified would have 

prevented the fatality (Drury & Brill, 1983). We identified up 

to five such contributing factors for each fatal report. Table 1 

shows the list of contributing factors and their definitions. 

After the preliminary coding and coding scheme 

development, two coders independently coded all 67 identified 

fatal reports. After coding, any discrepancies were resolved 

through discussion. If it was not possible to resolve 

discrepancies, a third independent coder was consulted. As 

part of the coding, it was identified that some fatal reports 

(four for metal/nonmetal and one for coal) that were initially 

identified as associated with a slip, trip, or fall were in fact due 

to other causes and were eliminated from further analysis. The 

fatalities eliminated were associated with individuals getting 

engulfed or drowning without a slip, trip, or fall event. The 

resultant data set accounted for 62 fatal reports (43 for 

metal/nonmetal and 19 for coal). 

RESULTS 

Job categories and activities 

Eighty-two percent of all identified fatalities could be 

attributed to four primary job categories: laborer, equipment 

operator, mechanic/maintenance man, and 

supervisor/management/trainer (Table 2). For the coal sector, 

a larger proportion of fatalities were attributed to laborers and 

supervisor/management/trainer as compared to the 

metal/nonmetal sector. In contrast, the metal/nonmetal sector 

had a larger proportion of fatalities attributed to equipment 

operators and truck drivers as compared to the coal sector. The 

proportion of fatalities was the same for the 

mechanic/maintenance man for both sectors. 

Table 1: Contributing factors and their definitions 

Contributing 

Factor

Definition

Barriers Barriers not present, not properly installed or 

inadequate 

EquipmentrelatedAny equipment-related issues, including use 

of broken or damaged equipment, 

unintended/improper use of equipment, 

modifications to equipment not 

recommended by manufacturer, failure of 

equipment, improper design of equipment

Fall protection Fall protection not used or not used 

appropriately

Housekeeping Contaminants on working surface

Illumination Lack of adequate illumination 

Lockout/tagout & 

blocking

Failure to properly de-energize, 

lockout/tagout and/or block equipment to 

resist movement

Medical 

complications 

Victim had a medical complication after 

initial injury that led to fatality

Operating 

procedure

No safe working procedures provided (either 

from management or manufacturer) 

including no training on procedures

Personal 

protective 

equipment

Personal protective equipment (PPE) not 

available or not used (other than fall 

protection), PPE not used appropriately, 

incorrect type of PPE used

Structural/ground 

failure

Failure of building, walking surface, unstable 

ground (at time of incident) 

Substance abuse Person under the influence of a controlled 

substance at time of incident

Table 2: Job categories for individuals who were fatally injured 

Job categories

Coal

n (%)

Metal/ 

nonmetal

n (%)

Total

n (%)

Laborer 8 (42.1) 10 (23.3) 18 (29.0)

Equipment operator 2 (10.5) 12 (27.9) 14 (22.6)

Mechanic/maintena

nce man 3 (15.8) 7 (16.3) 10 (16.1)

Supervisor/manage

ment/trainer 6 (31.6) 3 (7.0) 9 (14.5)

Truck driver - (0.0) 6 (14.0) 6 (9.7)

Contractor - (0.0) 3 (7.0) 3 (4.8)

Owner - (0.0) 2 (4.7) 2 (3.2)

The largest proportion of fatalities (37%) occurred when 

performing maintenance and repair activities (Table 3). 

Installation/construction/dismantling accounted for 18% and 

daily operations also accounted for 18% of the identified 

fatalities. On occasion, job categories did not correspond 

directly to the work activities—for example, at the time of the 

fatality, a laborer may have been inspecting equipment or a 

1667
truck driver may have been conducting routine maintenance. 

For the coal sector, a larger proportion of fatalities were 

attributed to installation/construction/dismantling and 

inspection as compared to the metal/nonmetal sector. In 

contrast, the metal/nonmetal sector had a larger proportion of 

fatalities attributed to maintenance and repair and daily 

operations as compared to the coal sector. 

Event or cause of fatality 

The primary cause (approximately 60%) of all fatalities 

identified was a fall from height for both sectors (Table 4). 

Although in 10 (27%) of the cases it was not clear what led to 

the fall from height (secondary cause), based on the fatal 

reports 50% of the fall from height fatalities were due to 

falling through an opening, failure of the ground/equipment, 

or being ejected from/thrown off of equipment (Figure 1). 

Table 3: Activities being performed at the time of the incident 

Job categories

Coal

n (%)

Metal/ 

nonmetal

n (%)

Total

n (%)

Maintenance and 

repair 4 (21.1) 19 (44.2) 23 (37.1)

Installation/

construction/

dismantling

7 (36.8) 4 (9.3) 11 (17.7)

Daily operations 2 (10.5) 9 (20.9) 11 (17.7)

Housekeeping (0.0) 5 (11.6) 5 (8.1)

Inspection 3 (15.8) 2 (4.7) 5 (8.1)

Supervising 1 (5.3) 2 (4.7) 3 (4.8)

Unknown 2 (10.5) 2 (4.7) 4 (6.5)

Table 4: Primary cause of fatalities and number of incidents 

associated with each cause 

Primary cause

Coal

n (%)

Metal/

nonmetal

n (%)

Total

n (%)

Fall from height 11 (57.9) 26 (60.5) 37 (59.7)

Fall from 

stairs/ladder 4 (21.1) 2 (4.7) 6 (9.7)

Fall into water 2 (10.5) 4 (9.3) 6 (9.7)

Engulfed/fall into 

material - - 4 (9.3) 4 (6.5)

Fall into equipment - - 4 (9.3) 4 (6.5)

Fall from 

truck/trailer - - 3 (7.0) 3 (4.8)

Fall to same level 1 (5.3) - - 1 (1.6)

Struck by 1 (5.3) - - 1 (1.6)

Figure 1: Secondary causes that led to fall from height fatalities 

27%

22%

16%

11%

8%

8%

5%

3%

Unknown

Fall through opening

Failure of ground/floor/equipment

Ejected from/thrown off equipment

Fall through roof

Unexpected movement

Slip

Fall from high wall

Approximately 10% of the identified fatalities (Table 4) 

were due to fall from stairs/ladders, half of which were due to 

a slip or unexpected movement of the stairs/ladder. Falling 

into water also accounted for approximately 10% of the 

fatalities. Additional causes of fatalities identified were 

engulfed by material, fall into equipment, fall from 

trailer/truck, and fall to same level. The one struck by incident 

was an unusual case where an individual fell off a piece of 

equipment and the equipment rolled onto the individual while 

the individual was still on the ground. 

Contributing factors 

Fall protection not being used when it should have been 

or not being used appropriately (incorrect type for situation or

tying off incorrectly) contributed to 33% of the fatalities 

identified (Table 5). Equipment related issues including 

broken, damaged, modified, failed, improper use of, and 

design of equipment contributed to 14% of the fatalities. The 

lack of and inadequate barriers contributed to 13% of the 

fatalities and was most often due to an individual stepping 

into/onto an opening in the ground. In addition, safe operating 

procedure contributed to 12% of the fatalities. The other 

contributing factors associated with slip, trip, and fall fatalities 

are shown in Table 5. There were some differences between 

the coal and metal/nonmetal sectors. For the metal/nonmetal 

sector, three factors—fall protection, barriers, and operating 

procedure—accounted for approximately 67% of the 

identified contributing factors. In contrast, for coal, two 

factors—fall protection and equipment-related factors—

accounted for approximately 50% of the identified 

contributing factors. 

DISCUSSION & RECOMMENDATIONS 

The objectives of this investigation were to identify job 

categories, activities, causal factors, and contributing factors 

for slip, trip, and fall fatalities at surface mining facilities. 

Laborer, equipment operator, mechanic/maintenance man, and 

supervisor/management/trainer were most often the victims of 

a fatal slip, trip, or fall incident at surface mining facilities. 

This is not surprising as there is evidence that maintenance 

and repair workers are exposed to slip, trip, and fall hazards; 

including working on debris and wet surfaces (Heberger, 

Nasarwanji, Paquet, Pollard, & Dempsey, 2012). 

1668
Table 5: Contributing factors associated with slip, trip, and fall 

fatalities 

Contributing 

Factors

Coal

n (%)

Metal/

nonmetal

n (%)

Total

n (%)

Fall protection 11 (27.5) 27 (36.0) 38 (33.0)

Equipment-related 9 (22.5) 7 (9.3) 16 (13.9)

Barriers 2 (5.0) 13 (17.3) 15 (13.0)

Operating procedure 4 (10.0) 10 (13.3) 14 (12.2)

Lockout/tagout & 

blocking 3 (7.5) 7 (9.3) 10 (8.7)

Structural/ground 

failure 1 (2.5) 6 (8.0) 7 (6.1)

Medical 

complications 3 (7.5) 2 (2.7) 5 (4.3)

Personal protective 

equipment 1 (2.5) 3 (4.0) 4 (3.5)

Housekeeping 2 (5.0) - - 2 (1.7)

Illumination 2 (5.0) - - 2 (1.7)

Substance abuse 2 (5.0) - - 2 (1.7)

Fatalities associated with maintenance and repair were 

studied extensively by Reardon et al. (2014), as they are a 

significant contributor for fatalities in the mining industry. Our 

findings provide further support for the thesis that 

maintenance and repair, construction, and installing and 

dismantling equipment are hazardous activities. These 

activities pose a threat as equipment is often not designed for 

maintenance and repair, and during these activities the system 

is in flux. Because some of the hazards during maintenance 

and repair cannot be engineered out, care should be taken to 

limit access when possible and use appropriate PPE. 

The leading cause of slip, trip, and fall fatalities at surface 

sites was a fall from height (approximately 60%). By 

comparison, the largest proportion of non-fatal fall injuries at 

surface sites is due to falls to walkway or walking surfaces 

(approximately 40%) (Mine Safety and Health Administration, 

2003-2012). Although it is unclear if the falls to walkway or 

walking surface were from a height, there may be differences 

in the hazards that cause slip, trip, and fall fatalities and nonfatal injuries, and likewise in the strategies to identify and 

remediate them. A few contributing factors for fatalities are 

described here, but additional research is needed to identify 

the cause and contributing factors for non-fatal injuries to help 

remediate them. 

All fatalities identified had at least one contributing factor 

that if mitigated could have potentially prevented the incident 

or lessened the severity of the injury. Guidelines suggest that 

preventing access or restricting work in hazardous areas is 

preferable (Occupational Safety Health Administration, 2003). 

As revealed by the fatal reports, the lack of barriers or 

inadequate barriers was a contributing factor to slip, trip, and 

fall fatalities. Chi et al. (2005) found a similar trend for fall 

fatalities in the construction industry, where unguarded 

openings was the leading contributing factor. 

During maintenance, repair, or installing and dismantling 

equipment, areas of the walking surface are often removed to 

permit or improve access to the equipment. Special care 

should be taken in these situations to ensure that appropriate 

barriers are installed immediately around the opening to 

prevent inadvertent access. In addition, during regular 

operations, debris can cover surfaces that are not designed to 

support the weight of an individual such as skylights. These 

areas should also be kept free of debris and clearly marked or 

barricaded off to prevent inadvertent access. When 

housekeeping around these areas is undertaken, such as to 

remove debris, work should proceed with caution, so as to not 

tread on those surfaces. In addition, any temporary flooring, 

such as wooden panels, should be inspected regularly. 

If barriers cannot be provided and access cannot be 

restricted, the use of fall protection is recommended when 

working at heights. The use of fall protection may have 

prevented a number of the fatalities identified; however, it is 

not clear why fall protection was not used. It would be 

beneficial to further evaluate the risk perception of individuals 

in these situations and identify why fall protection was not 

used. In some cases, such as fall through an opening or where 

barriers were inadequate, the individuals may not have felt 

that they were at risk and hence assumed they did not need the 

fall protection. In other instances, incorrect fall protection was 

used or the fall protection was not used appropriately (e.g., not 

tied off suitably). Providing adequate and appropriate fall 

arrest systems, including harnesses that are easily accessible, 

fitted to the individual, and designed for the specific task, and 

clearly marked and substantial tie off points, is essential for 

the safety of employees along with adequate training to ensure 

proper use. 

Most equipment-related factors can be controlled, 

including broken, damaged, and modified or failed equipment. 

Regular inspection and maintenance of equipment is essential 

for not only the health and safety of employees but also for 

efficient operations. In addition, companies should be 

responsible for providing employees with safe working 

procedures and adequate training. Performing a hazard 

assessment before any task can help to identify hazards and 

ensure adequate safety precautions are taken to remediate 

them or prevent an incident. 

CONCLUSIONS 

The objective of this paper was to identify the causes and 

contributing factors to slip, trip, and fall fatalities at surface 

mining operations. Most fatalities were associated with a few 

job categories and common activities. Maintenance and repair 

has been shown to be a hazardous task for other types of 

fatalities, and the same holds true for slips, trips, and falls. Fall 

from height was the primary cause of most fatalities. In 

addition, limiting access through the use of adequate and 

appropriate barriers and using appropriate fall protection is 

critical in preventing fatalities along with regular inspection 

and maintenance of equipment. 

1669
ACKNOWLEDGMENTS 

I would like to thank Leanna Reardon for her help 

developing the coding scheme and coding of the fatal reports. 

I would also like to acknowledge Jonisha Pollard for her 

assistance resolving discrepancies in the coding. 

DISCLAIMER 

The findings and conclusions in this manuscript are those 

of the author and do not necessarily represent the views of the 

National Institute for Occupational Safety and Health 

(NIOSH). Mention of any company or product does not 

constitute endorsement by NIOSH. 

REFERENCES 

Bell, J. L., Collins, J. W. D., Dalsey, E., & Virginia, S. (2010). 

Slip, Trip, and Fall Prevention for Healthcare 

Workers: NIOSH. 

Chi, C.-F., Chang, T.-C., & Ting, H.-I. (2005). Accident 

patterns and prevention measures for fatal 

occupational falls in the construction industry. 

Applied Ergonomics, 36(4), 391-400. doi: 

http://dx.doi.org/10.1016/j.apergo.2004.09.011

Courtney, T. K., Sorock, G. S., Manning, D. P., Collins, J. W., 

& Holbein-Jenny, M. A. (2001). Occupational slip, 

trip, and fall-related injuries - can the contribution of 

slipperiness be isolated? Ergonomics, 44(13), 1118-

1137. doi: 10.1080/00140130110085538 

Drury, C. G., & Brill, M. (1983). Human Factors in Consumer 

Product Accident Investigation. Human Factors: The 

Journal of the Human Factors and Ergonomics 

Society, 25(3), 329-342. doi: 

10.1177/001872088302500310

Drury, C. G., Porter, W. L., & Dempsey, P. G. (2012). 

Patterns in Mining Haul Truck Accidents. 

Proceedings of the Human Factors and Ergonomics 

Society Annual Meeting, 56(1), 2011-2015. doi: 

10.1177/1071181312561420 

Heberger, J. R., Nasarwanji, M. F., Paquet, V., Pollard, J. P., 

& Dempsey, P. G. (2012). Inter-Rater Reliability of 

Video-Based Ergonomic Job Analysis for 

Maintenance Work in Mineral Processing and Coal 

Preparation Plants. Proceedings of the Human 

Factors and Ergonomics Society Annual Meeting, 

56(1), 2368-2372. 

Lipscomb, H. J., Glazner, J. E., Bondy, J., Guarini, K., & 

Lezotte, D. (2006). Injuries from slips and trips in 

construction. Applied Ergonomics, 37(3), 267-274. 

doi: http://dx.doi.org/10.1016/j.apergo.2005.07.008

Mine Safety and Health Administration. (2003-2012). Mining 

Industry Accident, Injuries, Employment, and 

Production Statistics and Reports. Retrieved 

September 2013, from 

http://www.cdc.gov/niosh/mining/data/default.html

Occupational Safety Health Administration. (2003). Personal 

Protective Equipment, OSHA 3151-12R 2003, US 

Department of Labor. 

Reardon, L. M., Heberger, J. R., & Dempsey, P. G. (2014). 

Analysis of Fatalities During Maintenance and 

Repair Operations in the U.S. Mining Sector. IIE 

Transactions on Occupational Ergonomics and 

Human Factors, 2(1), 27-38. doi: 

10.1080/21577323.2014.911222 

1670