MIFACE INVESTIGATION REPORT #16MI104

SUBJECT: Concrete Finisher Electrocuted When Bull Float Contacted an 

Energized Power Line

Summary

In the summer of 2016, a male concrete finisher in his 30s was electrocuted when the handle of 

the 29-foot-long metal bull float he was using contacted an energized 7,200 volt power line. The 

decedent and his coworkers were performing concrete finishing work for a residential driveway. 

The decedent was facing south, finishing the concrete driveway and the power lines were at his 

back (north) when the 

incident occurred. A line of 

brush was approximately 8 

feet away from him under 

the power lines, which may 

have required him to 

elevate the bull float 

handle rather than pull it in 

a more horizontal position. 

The decedent was wearing 

non-electrical rated rubber 

boots over his leather work 

boots, vinyl work gloves, 

hard hat and safety glasses. 

When the bull float handle 

contacted the overhead 

line, the decedent fell 

forward, letting go of the 

pole. The utility company measured the height of the two overhead lines after the incident. The 

bottom neutral line was 17 feet high and the 7,200-volt primary line was 23-feet high vertically 

and 24 feet from the edge of the concrete forms. There were two visible impact burn points on 

the wire. One was a 1.5-2-inch width of the bull float pole and the second contact was 

approximately 2.3-3.0 feet long where the pole may have slid along the wire. Emergency 

response was called and the decedent was transported to a local hospital where he died.

MIFACE identified the following key and possibly contributing factors: 

• Unfamiliarity with residential jobsites and associated hazards relating to nearby, aboveground power lines. 

• Failure to identify and assess power lines as hazards and make appropriate 

recommendations to employees regarding work practices and equipment. 

• Use of conductive bull float handles. 

Figure 1: Overview of incident scene
RECOMMENDATIONS

• Conduct a jobsite survey and hazard assessment to identify all potential hazards, 

including those associated with overhead power lines. 

• Institute a hazard awareness program in which employees are educated about potential 

hazards as well as any specific hazards noted during the jobsite survey. 

• When working near overhead power lines, ensure that a minimum of 10 feet of space is 

maintained between the equipment and the power line. 

• Contact the power company to alert them about the work being performed near power 

lines. 

• Use bull float handles that are non-conductive and/or insulated. 

BACKGROUND

In the fall of 2016, a male concrete finisher in his 30s was electrocuted when the metal handle of 

his 29-foot-long metal bull float he was using to smooth concrete contacted an energized 7,200 

volt power line overhead. MIFACE researchers became aware of the fatality via the MIOSHA 

24-hour ASAP reporting system. The owner, who was the father of the decedent, agreed to 

participate in the research after being contacted by MIFACE. The MIFACE researcher visited 

the work site and, with the permission of the family member, the MIFACE researcher took 

photographs of the incident site. During the writing of this report, the death certificate, medical 

examiner and police reports, and the MIOSHA compliance file were reviewed. The pictures used 

in this report are courtesy of MIOSHA compliance file. 

The decedent was a foreman and concrete finisher for a concrete contractor. He was one of 20 

employees at the time of the incident. The company had been operating for 40 years, and the 

decedent had worked full-time for this company for 15 years total, and the past 5 years 

consecutively following a 5-year hiatus working for another contractor. The company normally 

performed work such as pouring foundations for larger commercial or industrial projects, but 

was pouring concrete for a driveway in a residential lot neighboring the company’s location 

during the incident. The decedent normally worked 10-12 hour shifts. 

The company had in place a written accident prevention plan aiming to address site-specific 

hazards. Additionally, although the company regularly held toolbox talks regarding safety issues, 

the owner didn’t believe the topic of overhead power lines had ever been covered, since their 

normal work involved foundation-pouring projects, where the sites were in wide-open areas and 

power lines had either not been installed or were located underground. The decedent had 

received formal safety training during his 5 years at another company, although it is unknown if 

this training included overhead power line safety.

The company had been using bull floats with aluminum handles for many years to smooth the 

concrete after leveling. These handles were preferred for their light weight, low cost, and 

durability. The business owner indicated during the interview that he has since switched to using 
fiberglass handles, which are slightly heavier and approximately the same cost but are markedly 

less conductive. 

Company Remediation 

Since the incident, the company has conducted employee training specifically regarding hazard 

assessment and identification for overhead power lines. Additionally, following the incident and 

subsequent MIOSHA investigation, the owner in conjunction with MIOSHA and the power 

company held a training seminar for other contractors to raise awareness about the hazards 

presented by overhead power lines and ways to prevent similar incidents from happening. A 

representative of a manufacturer of fiberglass handles was also present at the event, in an effort 

to encourage and facilitate the use of non-conductive handles by other contractors.

MIOSHA Citations

MIOSHA Construction Safety and Health Division issued the following Serious citations to the 

company at the conclusion of its investigation: 

SERIOUS: GENERAL RULES, CS PART 1, RULE 408.40115(5): Employees not specifically 

covered by Construction Safety Standard Part 16 Power Transmission and Distribution, 

Construction Safety Standard Part 17 Electrical Installations, or Construction Safety Standard 

Part 30 Telecommunications, as referenced in R 408.40105, shall not be allowed by the 

employer to work or be closer to energized electrical line, gear, or equipment exposed to contact 

than the minimum clearance. 

Employee using equipment closer than allowable distance to 7200-volt overhead power 

line. 

SERIOUS: CONCRETE CONSTRUCTION, CS PART 25, RULE 408.42520(3): The handle on 

a bull float that is used where it may contact an energized electrical conductor shall be 

constructed of non-conductive material or shall be insulated with a non-conductive sheath that 

has electrical and mechanical characteristics which provide the equivalent protection of a handle 

constructed of non-conductive material.

An employee was engaged in concrete finishing work, when the 29-foot aluminum 

handle of his bull float came in contact with a 7200-volt overhead power line. 

INVESTIGATION

The company was pouring an approximately 30-35 cubic yard concrete slab for a residential 

driveway, with the garage of the house facing north and the driveway extending from the front of 

the garage east down a hill to the street. On the north edge of the driveway was a line of trees, 

and then a small gulley that deepened as the hill rose to the west, separating the property from 

the neighboring lot to the north (where the concrete company was located, on a hill across the 

gully). The power line extended east-west along this property line, with the poles extending into 

the gulley. At the bottom of the hill, along the street, the neutral and 7,200 V energized power 
lines ran on opposite sides of the pole, but switched to being paired vertically (with the neutral 

line on the bottom, and the energized line on top) by the time they reached the pole near the 

northwest corner of the driveway. The company had backed a cement truck up near the garage, 

and they had begun pouring at the face of the garage that morning from south to north. 

The decedent arrived at the site as one of 10-12 workers present that day at 7:00 AM. The area to 

be poured was delineated with pieces of lumber, which were in turn held in place with metal pins 

driven into the ground. Concrete 

pouring commenced around 8:00

AM. The decedent was reported 

to have used a bull float attached 

to four or five 6-ft aluminum 

handles connected in sequence, 

which gave him approximately 

24-30 feet of reach. This was

corroborated by the MIOSHA 

investigation that stated that the 

bull float had 29 total feet of 

reach. The handles were 

connected to the float via a 

mechanism that altered the angle 

of the handle-float joint via the 

axial rotation of the handles, 

which allowed for the float to 

maintain level contact with the concrete along the length of its use without progressively 

elevating the handle as the float was drawn nearer (Figure 2). 

As the slab being poured was approximately 33 feet wide, the decedent had to walk around the 

edge of the slab in order to reach the entirety of the concrete being poured. The decedent began 

the process of smoothing the poured concrete on a patch of lawn directly adjacent to the garage, 

in the southwest corner of the driveway. From there, he moved north along the western edge of 

the driveway repeating the process, before he relocated along the northern edge of the driveway 

around 9:30 AM (Figure 1, photo facing north).

Once along the northern edge of the driveway, the decedent was unable to hold or use the 

entirety of the bull float handles horizontally, as the vegetation along the top of the gully began 

approximately 8 feet behind him (Figure 3). This may have required him to elevate the 29-foot 

handle more than usual. Once elevated, the handle made contact with the energized power line. 

Figure 2: Bull float used by decedent.
Witnesses say they heard a 

popping noise and saw the 

decedent’s body give way, and 

that he began to lower the float

handle. At this point the metal 

float head contacted steel pins 

holding the wooden form around 

the pouring site, grounding the 

circuit and further electrocuting 

the decedent and causing the 

fuse for the power line to blow.

The power lines had been noted 

during an initial site assessment 

the previous week he had noted 

the power lines. Similarly, the 

MIOSHA investigation found

that in the days leading up to the incident some work had been done to prepare the area 

underneath and around the overhead line, and that workers had made note of the pole and lines.

However, the owner stated that the lines and their hazards were not discussed with the work crew 

in the planning of the project. During the MIOSHA investigation, one member of the work crew 

noted that previous power line hazards had been discussed informally when they were noticed. It 

is unknown whether the decedent or other present during the incident were aware of the power 

lines or the hazard they represented.

While the owner was aware of the availability of non-conductive handles and had used them in 

the past, he stated that they did not use them regularly because of their increased weight 

compared to the aluminum handles, that non-conductive handles were less durable, and the holes 

through which the non-conductive handles screwed into the mechanism on the float that enables 

the angle of the float to be changed via the rotation of the handle would widen with use, 

requiring a greater rotation for a given change in angle and decreasing the mechanism’s

efficiency. Consequently, each of the handles connected to the float used by the decedent were 

composed of aluminum. 

According to the police report, the energy company took measurements of the power lines after 

the incident, and found the bottom neutral line to be 17 feet above grade, while the top energized 

line was 23 feet above grade and 24 feet from the edge of the work site at an angle (at about 8 

feet away horizontally). There were two burn points on the energized line, one was 1.5-2 inches 

wide (approximately the width of the handle), and the other was 2.3-3 feet long, suggesting the 

handle slid along the power line. The owner suggested that the fact that the pole supporting the 

power lines was situated in the gulley further contributed to the death since the vertical distance 

to the power lines from the driveway was not the full height of the pole.

The decedent was reported to not be wearing any personal protective equipment (PPE) at the 

time of the incident, although the police report noted that he had been wearing work boots and 

Figure 3: Vegetation along north end of worksite
black rubber concrete boots. The MIOHSA report stated that the decedent was wearing eye 

protection and a hard hat. None of this PPE would have provided protection from an 

electrocution.

Once the decedent had been electrocuted, one coworker began administering CPR, while another 

ran to get the owner from the company’s property to the north. Emergency response was called, 

and the decedent died later at a local hospital.

CAUSE OF DEATH

The cause of death as listed by the medical examiner on the death certificate was electrocution.

The victim was found to have ibuprofen, nicotine, and caffeine in his blood; all other 

toxicological tests were negative.

RECOMMENDATIONS/DISCUSSION

• Conduct a jobsite survey and hazard assessment to identify all potential hazards, 

including those associated with overhead power lines. 

Both the MIFACE interviews as well as the MIOSHA investigation found that the power lines 

were noted during job planning and preparation, with space below the lines being cleared ahead 

of the day of the incident, although it did not appear that the hazards associated with the power 

lines were communicated to the workers present on the day of the death. Prior to the start of a 

project, employers should conduct a worksite inspection, note any potential hazards to 

employees and take steps to plan and implement appropriate controls to minimize the risks posed 

by the project. The use of a hazard assessment checklist or other standardized form can help 

remind those conducting the survey of potential hazards to look for, even if they are rare or 

unusual for the typical work performed by the contractors. Furthermore, the presence of any 

noted hazards should be communicated to the contractors working at the site. In this case, such 

an assessment could have noted both the presence of the power lines themselves, their height in 

relation to the bull float handles to be used, and the nearby tree line that would’ve complicated 

ideal use of the float and the maintenance of a safe distance from the lines.

• Institute a hazard awareness program to educate employees about the potential and 

specific hazards noted during the jobsite survey and how to minimize exposure to these 

hazards.

Regular training for employees in hazard awareness and identification encourages employees to 

remain vigilant regarding worksite hazards to themselves and their coworkers. Additionally, 

specific discussions before the start of a project, such as toolbox talks, regarding any hazards 

identified for the particular worksite and their pertinent controls, in conjunction with warning 

signage, ensures that employees are aware of these hazards and equipped to control and mitigate 

them. No such communication regarding the power lines, or the vegetation that would require 

elevating the float handle near the lines, was given prior to the start of the project on the day of 

the incident. MIFACE recommends site-specific reminders of electrocution hazards during 

toolbox talks preceding any project when energized overhead power lines have been identified in 
the site survey, as well as the controls (including work practices and equipment) to be used to 

eliminate the hazards at the worksite. Additionally, it is recommended to either place warning 

signs at the worksite in the vicinity of the power lines to continually remind workers of the 

hazards, or to restrict entry to the vicinity. 

• When working near overhead power lines, ensure that a minimum of 10 feet of space is 

maintained between the equipment and the power line.

MIOSHA Construction Safety Standards, Part 1 Rule 40115 dictates that workers may not be 

within 10 feet of any energized electrical lines, gear, or equipment for voltages up to 50 kV. The 

absence of training focusing on power lines likely meant that the employees at the worksite were 

not aware of this standard and did not organize the work site to ensure its implementation 

throughout the project. The bull float with a 29 foot handle that was used on the north side of the 

worksite underneath the lines against a line of vegetation required the elevation of the handle 

thus and likely necessitated violating the 10 feet of clearance. Other work practices, such as the 

use of a longer handle from other sides of the driveway might have been implemented if this 

standard was being observed. As discussed above, signage or an area restriction can be used to 

keep workers aware of the extent of the 10-foot clearance area.

• Contact the power company to alert them about the work being performed near power 

lines. 

Contacting the power company before beginning a project can provide information regarding 

whether lines are energized, the heights of the lines, and instructions for safe work practices. A 

representative from the power company may be able to come to the work site to perform a 

project-specific assessment and make further safety recommendations. If appropriate clearance 

around the energized line cannot be guaranteed due to constraints of the work site and project, 

contact the power company to request that they be de-energized for the duration of the project. 

• Use bull float handles that are non-conductive and/or insulated. 

MIOSHA Construction Safety Standard, Part 25 Rule 2520 states that the handle of a bull float 

being used near an energized electrical conductor must be either constructed of nonconductive 

material or insulated in a nonconductive sheath. These requirements aside, according to the 

employer he and many other contractors are aware of the availability of such nonconductive 

handles, but have frequently chosen to continue using aluminum handles because of weight and 

durability concerns. However, these concerns can be mitigated at least partially by restricting the 

use of non-aluminum handles to only those work sites where electrical hazards have been 

identified during the worksite hazard assessment, prolonging the lifespan of the non-aluminum 

handles. Worker rotation can also be used if the increased weight of non-conductive handles 

leads to more frequent exhaustion on the part of the worker using the float. Since the incident, 

the employer has purchased multiple fiberglass handles and has instructed employees to use 

them when working near overhead power lines. 

KEY WORDS: Electrocution, Power Lines, Bull Float, Concrete, Construction 
RESOURCES

MIOSHA standards cited in this report may be found at and downloaded from the MIOSHA, 

Michigan Department of Licensing and Regulatory Affairs (LARA) website at: 

http://www.michigan.gov/lara/0,4601,7-154-11407_15368---,00.html. MIOSHA standards are 

available by writing to: Michigan Department of Licensing and Regulatory Affairs (LARA), 

MIOSHA Regulatory Services Section, Stevens T. Mason Building, 530 W. Allegan Street, 

Lansing, Michigan 48933, calling (517) 284-7740, or by FAX (517) 284-7735. 

• MIOSHA Construction Safety Standard, Part 1. General Rules: 

http://www.michigan.gov/documents/lara/lara_miosha_cs_part_1_426600_7.pdf

• MIOSHA Construction Safety Standard, Part 25. Concrete Construction: 

http://www.michigan.gov/documents/CIS_WSH_part25_35542_7.pdf

MIFACE (Michigan Fatality Assessment and Control Evaluation), Michigan State University 

(MSU) Occupational & Environmental Medicine, 909 Fee Road, 117 West Fee Hall, East 

Lansing, Michigan 48824-1315; http://www.oem.msu.edu. This information is for educational 

purposes only. This MIFACE report becomes public property upon publication and may be 

printed verbatim with credit to MSU. Reprinting cannot be used to endorse or advertise a 

commercial product or company. All rights reserved. MSU is an affirmative-action, equal 

opportunity employer.