DATE: 

June 15, 2017

TIME:

9:45 a.m.

VICTIM:

57-year old municipal 

equipment operator

INDUSTRY/NAICS CODE:

Public Works / 237110

EMPLOYER: 

Municipal public works

SAFETY & TRAINING:

No safety and health 

program and limited onthe-job training

SCENE: 

A pump station in a 

residential area

LOCATION:

Massachusetts

EVENT TYPE:

Crushing

___________________________

INCIDENT HIGHLIGHTS 

 

REPORT#: 17MA018 REPORT DATE: September 19, 2018

Equipment Operator Dies After Zero-Turn Mower 

Overturns—Massachusetts 

________________________________________________________

SUMMARY 

On June 15, 2017, a 57-year-old equipment operator was killed while 

operating a ride-on mower. At the time of the incident, the equipment 

operator was mowing grass at a municipality-owned pump station. As the 

operator turned the mower to the left, it struck a low-lying rock covered by 

vegetation. The mower overturned, pinning the operator against the 

ground. READ THE FULL REPORT> (p.3)

________________________________________________________ 

CONTRIBUTING FACTORS 

Key contributing factors identified in this investigation include:

 Mower was operated across a slope greater than 15 degrees; 

 Mower was operated while rollover protective structures (ROPS) were 

in the folded down position; 

 Lack of a comprehensive safety and health program; and 

 Working alone. LEARN MORE> (p.9)

 _______________________________________________________ 

RECOMMENDATIONS 

Massachusetts FACE Program concluded that, to help prevent similar 

occurrences, employers should: 

 Ensure ride-on mower operators use ROPS and seatbelts when the 

mower is equipped with them. 

 Routinely perform job safety analyses before mowing begins to outline 

the proper equipment and practices are used to perform the task 

safely. 

 Ensure that ride-on mowers are not operated on slopes where the 

angle is greater than the maximum slope specified by the 

manufacturer. 

 Routinely provide employees with training on the equipment used to 

complete tasks. 

 Develop and implement a comprehensive safety and health program 

that addresses hazard recognition and avoidance of unsafe conditions. 

 Consider developing policies that prevent employees from working 

alone when performing certain tasks. LEARN MORE> (p.9) 
Page 2

Fatality Assessment and Control Evaluation (FACE) Program

The Massachusetts Department of Public Health, in cooperation with the National Institute for Occupational Safety and Health 

(NIOSH), conducts investigations on the causes of work-related fatalities. The goal of this program, known as Massachusetts 

Fatality Assessment and Control Evaluation (Massachusetts FACE) is to prevent future fatal workplace injuries. Massachusetts 

FACE aims to achieve this goal by identifying and studying the risk factors that contribute to workplace fatalities, by recommending 

intervention strategies, and by disseminating prevention information to employers and employees. 

NIOSH funded state-based FACE Programs currently include: California, Kentucky, Massachusetts, Michigan, New York, Oregon, 

and Washington.
REPORT#: 17MA018 Page 3

SUMMARY 

On June 15, 2017, a 57-year-old equipment operator was killed while operating a ride-on mower. At the time of the 

incident, the equipment operator was mowing grass at a municipality-owned pump station. As the operator turned the 

mower to the left, it struck a low-lying rock covered by vegetation. The mower overturned, pinning the operator against 

the ground. A motorist passing by noticed the overturned mower, stopped, and placed a call for emergency medical 

services (EMS).

INTRODUCTION 

On June 15, 2017, a municipal equipment operator was fatally injured when the zero-turn mower he was operating 

overturned. The Massachusetts FACE Program was notified by the local police department about the incident on the 

same day. On June 16, 2017, representatives from the Massachusetts FACE Program and the Massachusetts 

Department of Labor Standards traveled to the municipality where the incident occurred and met with multiple 

representatives from the town’s police and public works departments to discuss the incident. The police report, death 

certificate, and other information were reviewed. 

EMPLOYER

The employer was a local municipal Department of Public Works for a Massachusetts town with a population of 

approximately 8,900 residents. The town was incorporated in the early 1900’s. The Department of Public Works had a 

highway division and a water and sewer division. The public works department had about five equipment operators at 

the time of the incident, including the victim. These employees typically worked 8 hours per day with shifts routinely 

starting at 7:00 a.m. and ending at 3:30 p.m., Monday through Friday. The main tasks for equipment operators included 

general maintenance that involved operating mowers, weed string trimmers, loaders, and skid-steer loaders. Most of 

the town’s non-management public works employees had union representation, as did the victim. 

WRITTEN SAFETY PROGRAMS and TRAINING 

At the time of the incident, the department did not have a comprehensive safety and health program. Workers were 

provided some basic training and were also provided with personal protective equipment (PPE), including hearing and 

eye protection and high visibility safety apparel. When the mower involved in the incident was purchased and delivered 

to the town, the distributor provided training on it. The town-owned trucks were equipped with radios and when 

employees were not in the trucks, they used personal cell phones for communication. 

WORKER INFORMATION 

The victim was a 57-year-old male municipal worker who had been employed as an equipment operator by the public 

works department for approximately 31 years. The victim held two Massachusetts Department of Public Safety and 

Inspections issued licenses. One was a hoisting engineer license and the other was a license to operate front end 

loaders and backhoes. 

INCIDENT SCENE 

The incident occurred at a town-owned pump station that was located one mile from the town center in a residential 

area. The pump station was a single story, wood framed, vinyl sided building on a 0.31 acre corner lot. The lot was 

mostly flat with two sloped areas along the east and west property lines. There was an asphalt driveway that led to the 

station, some vegetation along the south and west property lines, and the remaining land area was grass. 
REPORT#: 2017-18 Page 4

WEATHER 

The weather at the time of the incident was approximately 75 degrees Fahrenheit, 34% humidity, 12 mph average 

southerly wind speed, and mostly clear skies. There was no precipitation on the day of the incident and during the days 

leading up to the incident.1 The weather is not believed to have been a factor in this incident. 

EQUIPMENT 

The equipment being used at the time of the incident was a zero-turn mower that was equipped with a 23 horsepower 

gasoline engine and four tires (Figure 1). The front tires had a smooth tread and were 13 inch by 6 inch. The rear tires 

had a more aggressive tread and were 22 inch by 10 inch. The mower was equipped with a foldable ROPS (Figure 2), and 

the operator’s seat had a seatbelt and an interlock that shut off the engine if the operator left the seat while the parking 

brake was disengaged. 

Fig. 1: Mower involved in the Fig. 2: Mower with ROPS folded down Fig.3: Manufacturer warning 

incident decal 

 

The mower’s dimensions were 78.5 inches long, 62.25 inches wide (with chute down), 68 inches high with the ROPS 

extended and 48.5 inches high with the ROPS in the down position. The mower had a cutting width of 48 inches and a 

cutting height that was adjustable from 1 – 5 inches. The mower weighed approximately 918 pounds and had a forward 

maximum speed of 9 miles per hour and a reverse maximum speed of 5 miles per hour. 

The mower had two (right and left) levers that controlled speed and direction of travel. To move the mower in reverse,

both steering control levers would be pulled backward. To travel straight forward, both steering control levers would be 

pushed forward. To turn left, the left lever would be pushed back or the right lever would be pushed forward or a 

combination of both of these operations would be performed to make a tight turn or a gradual turn. To turn right, the 

right lever would be pulled back or the left lever would be pushed forward or a combination of both of these operations 

would be performed.

The mower had many warning decals that included messaging about operating the mower on slopes greater than 15 

degrees (Figure 3). The manufacturer-developed operator’s manual instructed to never mow slopes greater than 15 

degrees; a push mower or other equipment should be used for slopes steeper than 15 degree. The manual also 

instructed to mow up and down slopes and to never mow across slopes. The manual included information on the 

importance of using the equipped ROPS and seatbelt together at the same time. The manual stated that the foldable 
REPORT#: 2017-18 Page 5

ROPS should never be folded down when the mower is being used and that the ROPS should only be folded down, if 

needed, when transporting the mower. 

INVESTIGATION 

On the day of the incident, the victim arrived at the public works garage location at about 6:00 a.m. for his 7:00 a.m. 

shift. One of the victim’s tasks this day was mowing. The mowing task routinely occurred during the growing season. 

There was no set schedule and how often employees mowed depended on how quickly the grass grew. 

The victim transported the mower using an open trailer pulled by a town-owned pickup truck. The victim arrived at the 

pump station (Figure 4) at around 1:00 p.m. and unloaded the mower and started mowing. It appears that the he was 

mowing in the forward direction across a section of the sloped land along the east property line when the incident 

occurred. After the incident the slope was measured to be approximately 24 degrees (Figure 5). 

Fig. 4: Pump station where the incident occurred Fig. 5: Sloped land measured to approximately 24 degrees

 

The mowed path indicated the victim operated the mower across the slope, traveling towards the southern property 

line, which had vegetation and foliage along it. When the mower reached the area where the edge of the grass meets 

the edge of the vegetation and foliage (Figure 6) it appears the victim was making a 90 degree left turn, down the slope. 

During the turn, the mower’s right front tire struck a low rock (Figure 7) that was hidden by the low vegetation and 

foliage, causing the mower to overturn to the left and landed on top of the victim. The victim was pinned against the 

ground with the mower on top of him. 
REPORT#: 2017-18 Page 6

Fig. 6: Incident location where the grass meets the foliage Fig. 7: The rock that the mower right front tire struck

 

A passing motorist noticed the overturned mower, stopped, and then saw the victim face down with the mower’s seat 

against the middle section of his back. The motorist immediately placed a call for emergency medical services (EMS). A 

second motorist stopped and both motorists tried to lift the mower off the victim, but the mower was too heavy. 

Within minutes of the placed call, EMS arrived. Three firefighters and a police officer were able to lift the mower off the 

victim. Cardiopulmonary resuscitation (CPR) was started and the victim was transported to a local hospital where he 

was pronounced dead. 

The police reported that the victim was not wearing a seatbelt and that the rollover protective structure was not in use. 

The ROPS was folded and locked in the down position. During the site visit the ROPS was observed and its condition 

suggested that the ROPS was routinely not used due to the lack of wear and tear on the ROPS. 

CAUSE OF DEATH 

The medical examiner listed the cause of death as traumatic asphyxia. 

CONTRIBUTING FACTORS 

Occupational injuries and fatalities are often the result of one or more contributing factors or key events in a larger 

sequence of events that ultimately result in the injury or fatality. The Massachusetts FACE Program identified the 

following contributing factors in this incident: 

 Mower was operated across a slope greater than 15 degrees; 

 Mower was operated while the ROPS were in the folded down position; 

 Lack of a comprehensive safety and health program; and 

 Working alone. 
REPORT#: 2017-18 Page 7

RECOMMENDATIONS/DISCUSSION 

Recommendation #1: Employers should ensure that ride-on mowers are not operated on slopes where the angle is 

greater than the maximum slope specified by the manufacturer. 

Discussion: The manufacturer of the mower that was being used at the time of the incident included in the operator’s 

manual that the mower should not be operated on slopes greater than 15 degrees. Operating the mower on slopes 

greater than 15 degrees can result in the mower overturning. The manufacturer recognizes this hazard and stated in the 

operator’s manual that “Slopes are a major factor related to loss of control and tip-over accidents, which can result in 

severe injury or death.” Also on slopes less than 15 degrees, the manufacturer states that the mower should only be 

operated up and down the slope and never across the slope. 

In this case, the slope was measured to be 24 degrees at the location where the incident occurred. The ride-on mower 

should not have been used to mow this section of the grass. Since this slope was greater than 15 degrees, a push 

mower or string trimmer should have been used. In addition, because the mowing was being performed across the 

slope and not up and down the slope, this increased the mowers instability. 

Recommendation #2: Employers should ensure ride-on mower operators use rollover protective structures (ROPS) and 

seatbelts when the mower is equipped with them. 

Discussion: Employers should make sure that all manufacturer provided safety features are used at all times. The 

manufacturer had equipped the mower with both a rollover protective structure (ROPS) and a seatbelt.2 The ROPS and 

seatbelt should be used at the same time as they are designed to work together to protect the operator of the mower. 

In the event that the mower overturns, the ROPS will create a space underneath the mower and the seatbelt will help 

keep the operator within the created space. 

In this case, a foldable ROPS was provided by the manufacturer with the mower. Employers must ensure that foldable 

ROPS are locked in the upright position before operating the mower. Typically, foldable ROPS should only be folded 

down when the mower is being transported. If for some reason the mower has to be briefly operated with the ROPS 

folded down, for instance to avoid overhead obstruction, then the mower’s seatbelt should not be used by the operator 

while the ROPS is folded down. Once beyond the overhead obstruction, the ROPS should immediately be positioned 

back into the locked, upright position for regular use. 

Recommendation #3: Employers should routinely perform job safety analyses before mowing begins to outline the 

proper equipment and practices to be used to perform the task safely. 

Discussion: A job safety analysis (JSA) is a technique to systematically evaluate job tasks to ensure they are performed 

safely. It involves identifying potential hazards and hazardous situations that could occur when performing tasks by 

focusing on the relationship between the worker, the task, the tools, and the work environment.3 JSA should be 

routinely performed to identify uncontrolled hazards. Start by breaking down the tasks to be performed into steps, 

including the operation of any equipment and the use of tools to complete the task. Each step should be evaluated to 

identify the hazards or potential hazards. Once hazards are identified, employers should take steps to eliminate or 

control these hazards. It is important to have employees participate in the JSA. 

In this case, a JSA could have identified the potential hazards and unsafe conditions involved with the mowing task, such 

as the sloped land on the eastern property line being greater than 15 degrees. This could have led to a policy that a 

push mower or a string trimmer should be used and not a ride-on mower for the sloped area. In addition, the JSA would 

have identified any protrusions and objects that would present a hazard for a ride-on mower, such as the low-lying rock 

that was covered by vegetation. The next step would have been to ensure workers did not operate ride-on mowers on 
REPORT#: 2017-18 Page 8

the sloped area or too close to the edge of the vegetation and that a push mower or a string trimmer were used instead. 

To ensure it is clear to employees what equipment should be used in each area, an aerial map that indicates what type 

of equipment should be used to cut/trim the grass for each area could be generated (Figure 8). Also, identify other 

potential site hazards on the map, such as slopes great than 15 degrees and protrusions. Ensure that these maps are 

provided to the workers who will be completing the task. 

Fig. 8: Example of an aerial map showing the location 

 where the grass should not be cut by a ride on mower 

Recommendation #4: Employers should routinely provide employees with training on the equipment used to complete 

tasks. 

Discussion: Employers should provide workers with training before operating any equipment, including grass cutting 

equipment. Training ensures that the operator knows how to safely operate the equipment. Trainings should be 

performed by a competent person, which is defined by OSHA as “one who is capable of identifying existing and 

predictable hazards in the surroundings or working conditions which are unsanitary, hazardous, or dangerous to 

employees, and who has authorization to take prompt corrective measures to eliminate them”. Any training needs to 

be provided in the employee’s preferred language. This means the training must be provided in the language(s) and at 

the literacy level(s) of the employees. 

In this case, the training should cover topics on the safe operation and the limitations of the specific ride-on mower, and 

other equipment, that workers will use. These topics include: 

 Reviewing all safety devices provided by the manufacturer and ensuring that ROPS, seat belts, and guards are 

securely in place and properly used 

 Reviewing stability and roll-over hazards associated with operating the ride-on mower 

o Never operate a ride-on mower on an angle of greater than 15 degrees 

o Always mow up and down slope; never mow across slopes 

o Decrease speed when the mower is traveling down slopes or around sharp corners 

o Avoid all sudden starts, stops, or turns 

 Reviewing the importance of surveying the area for hazards and how to identify these hazards prior to beginning 

mowing and the areas where the use of ride-on mowers is prohibited 

 Always starting the mower from the driver's seat; never start the machine while standing beside it 

 Keeping both feet on the machine at all times while it is running and always perform proper shutdown 

procedures before dismounting. 
REPORT#: 2017-18 Page 9

 Always use personal protective equipment (PPE), including hearing and head protection, safety glasses, and 

work boots 

Retraining and evaluation are necessary to ensure that workers maintain their competency to operate a riding mower 

safely. Retraining should be provided for each employee as required (typically annually or every couple of years), when 

there is an incident, including incidents where no one was injured, and when employees are observed not operating the 

equipment properly. In addition, all training should be documented and the documentation should include who 

provided the training and their qualifications, the content of the training, workers who were trained, and the 

assessment of each worker’s comprehension of the training. 

Recommendation #5: Employers should develop and implement a comprehensive safety and health program that 

addresses hazard recognition and avoidance of unsafe conditions. 

Discussion: Having a municipality-wide safety and health program is an important part of keeping employees safe. A 

safety and health program should include the systematic identification, evaluation, and prevention or control of both 

general workplace hazards and the hazards of specific jobs and tasks. The core elements of an effective safety and 

health program are management leadership, worker participation, hazard identification and assessment, hazard 

prevention and control, education and training, and program evaluation and improvement.4 The program should outline 

safe work practices workers are expected to adhere to, specific safety protection for all tasks workers perform, how 

workers can identify and avoid hazards, and who workers should contact when safety and health issues or questions 

arise.4 The program should also include an explanation of the workers’ rights to protection in the workplace. 

When developing a safety and health program, employers should start by performing a hazard analysis of all routine 

tasks performed by employees for potential hazards and incorporate information about any identified hazards and their 

controls into the program.4 When determining potential hazards associated with equipment, information in the 

manufacturer operator’s manual and on the equipment’s warning labels should be reviewed and incorporated into the 

safety and health program procedures. 

Employers should also use their employees’ expertise throughout the program development process by seeking 

employee input. Once the program is developed, employers should continue to seek employees’ input during the 

routine updating of the program. The program should be updated when safety concerns arise and when new 

equipment, tasks and chemicals are introduced into the workplace. In addition, for situations where work sites change 

with each job, the safety and health program should also require that a job safety analysis be performed for each job 

site before work begins to ensure that the required tools and personal protective equipment (PPE) needed to complete 

the tasks are available. 

Employers should ensure that they have fully and effectively implemented their safety and health program by routinely 

performing assessments of tasks and immediately addressing any observed unsafe conditions. As part of the program’s 

implementation, training should be provided to all employees on the program’s topics and procedures, and should also 

include hazard recognition and the avoidance of unsafe conditions. All training provided to employees should be 

documented. In this case, the safety and health program should include a section on proper mower and other 

equipment selection, use of the equipment, and training. 

The Massachusetts Department of Labor Standards (DLS) offers free consultation services to help small employers 

improve their safety and health programs, identify hazards, and train employees. DLS can be contacted at 978-242-

1351. More information about DLS can be found on their website at www.mass.gov/dos/consult. 
REPORT#: 2017-18 Page 10

The Massachusetts Department of Industrial Accidents (DIA) has grants available for providing workplace health and 

safety training to employers and employees. Any company covered by the Massachusetts Workers’ Compensation 

Insurance Law is eligible to apply for these grants. More information about these DIA grants can be found on their 

website at www.mass.gov/dia/safety. 

Recommendation #6: Employers should consider developing policies that prevent employees from working alone 

when performing certain tasks. 

Discussion: Not all tasks rise to the level of ensuring that workers are not working alone, but some situations do. If the 

task involves a location away from other workers and a ladder will be used or large piece of equipment will be operated, 

especially when the operator is riding on the equipment, then it is a good idea to have at least two employees working 

together. Companies should consider developing policies that prevent workers from performing these types of tasks 

alone. 

Having a second person at the job site can also shorten the amount of time to complete the task. For lawn cutting tasks, 

while one employee uses a ride-on mower, the other employee could use a string trimmer or push mower. In this case, 

another reason to have more than one worker at a job site was the fact that the victim was transporting and operating a 

larger piece of equipment. If a co-worker was on site when the victim was pinned underneath the mower, the coworker could have potentially minimized the victim’s injuries by immediately assisted the victim and placing a call to

emergency medical services. 

ADDITIONAL RESOURCES 

OSHA. Dangers of Roll-Overs of Riding Mowers. www.osha.gov/dsg/riding_mowers/index.html 

KY FACE. Seasonal Lawn Mower Operator Crushed and Dies After Lawn Mower Rolls Over a 30 Degree Slope. 

www.cdc.gov/niosh/face/pdfs/15Ky041.pdf 

National Association of Landscape Professionals. www.landscapeprofessionals.org 

DISCLAIMER 

Mention of any company or product does not constitute endorsement by the National Institute for Occupational Safety 

and Health (NIOSH). In addition, citations to websites external to NIOSH do not constitute NIOSH endorsement of the 

sponsoring organizations or their programs or products. Furthermore, NIOSH is not responsible for the content of these 

websites. All web addresses referenced in this document were accessible as of the publication date. 

REFERENCES 

1. Weather Underground. Weather History. Massachusetts: TWC Product and Technology LLC. 

2. OSHA. Dangers of Roll-Overs of Riding Mowers. www.osha.gov/dsg/riding_mowers/index.html. Date accessed: April 

10, 2018. 

3. OSHA. Job Hazard Analysis. Publication Number: 3071. 

www.osha.gov/Publications/osha3071.pdf. Date accessed: April 10, 2018. 

4. OSHA. Recommended Practices for Safety and Health Programs. OSHA 3885. 2016. www.osha.gov/shpguidelines/. 

Date accessed: April 10, 2018.