FACE Program: Michigan Case Report 05MI095 | NIOSH

Michigan Case Report: 05MI095.

Summary

After the incident, he passed away roughly two weeks later. He had on all the necessary protective gear – a hard hat, safety vest, and safety glasses. The middle section of the limb fell and hit the deceased person (Figure 1). The knothole was covered by a nest made by a bird or squirrel. The fully barked, 8-inch wide middle section of the limb broke at its center due to a knothole that had decayed. When the limb of the tree being cut hit the trunk, it may have caused the tree itself to shake, which could have led to the almost vertically growing limb breaking at a weak point. The incident happened during the fourth cut. The crew had successfully completed three cuts on this limb; the cut limb fell away from the remaining limb, hit the tree trunk, and was then lowered down to the stake truck below using the friction rope. The deceased person was in charge of the friction rope used to lower the cut limb to the ground. The crew decided to remove the limb that extended over the pedestrian sidewalk because it was close to a house. One limb extended over the pedestrian sidewalk towards a house, one limb grew almost straight up, and one limb extended over the street. The deceased person, who was the supervisor on-site, and his crew had removed the smaller branches and were in the process of removing the three remaining major limbs. The tree was on city property and was considered a danger to residents. The limb broke and hit the deceased person on his head and shoulder when an overhead limb broke and hit him on his head and shoulder. A 51-year-old male municipal tree trimmer and his three coworkers were in the process of removing the branches from a dead silver maple tree that had a diameter of approximately 31 inches at its base on August 25, 2005.

Figure 1

Figure 1. Broken limb that struck decedent.

Figure 1. Broken limb that struck decedent.

Recommendations:.

  • Employers should evaluate tree-pruning operations and ascertain whether current rigging techniques could be enhanced with available technology.
  • Employers should ensure that crew sizes are sufficiently large to allow a site supervisor to effectively carry out their safety-related tasks.
  • Employers should establish standardized practices for safe tree trimming, including prohibiting employees from working under a dead tree limb and using an axe to handle tree limbs.
  • Introduction

    Photographs labeled as Figure 2 and Figure 3 were taken by the city police during their investigation. Figure 1, used as a photograph, was captured by the city safety technician during their investigation. MIFACE conducted interviews with the city safety technician, the supervisor, and union representatives from the city department where the deceased individual worked on September 21, 2005. The report writing process involved reviewing the police report, pictures, medical examiner’s report, city safety technician investigation report, and MIOSHA file and citations. On September 9, 2005, MIOSHA personnel informed MIFACE investigators about a work-related fatal injury that occurred and resulted in the death of the individual on the same day. The individual passed away approximately two weeks later due to complications from the injuries sustained on August 25, 2005. On that day, a 51-year-old male tree trimmer was struck by a tree limb that broke off from a weak spot.

    The work shift lasting for eight hours commenced at 7:00 a.M. And concluded at 3:30 p.M. He held a position as a full-time employee receiving payment on an hourly basis. The workforce was organized into a union. His job title was Tree Trimmer II, and he was assigned the role of an on-site supervisor. He had been employed by his current employer for a period of 15 years. The deceased individual possessed approximately 26 years of experience as a tree trimmer and had previously worked in the same capacity for other municipalities for a duration of eleven years. The city department, for which the deceased individual worked, held the responsibility of removing diseased and deceased trees from city property and surrounding areas.

    The deceased individual complied with all of the necessary requirements, as mandated by the city, which included wearing a helmet, protective eyewear, a reflective vest, and sturdy boots for this particular task. A documented protocol was established to address any violations related to health and safety. The department in which the deceased individual worked organized safety meetings on a monthly basis. Additionally, there was a committee comprised of both management and labor representatives that convened monthly to address health and safety matters. To enhance employee training, the city enlisted the assistance of a professional trade group and a paid private consultant. However, there were no written guidelines in place for the safe removal of branches and the cutting down of a deceased tree. Nevertheless, the city had a comprehensive safety and health program that was both documented and implemented.

    Evaluating and showcasing confirmed the employee’s proficiency. Documentation of training was upheld. Additionally, employees were sent to external locations to participate in specialized training initiatives offered by industry associations and equipment producers. The majority of training took place in the workplace and in a classroom setting, with the supervisor directly overseeing the process. The employer implemented a safety training program, which was jointly provided by both the employer and the union.

    MIOSHA did not record any circumstances that would result in the issuance of any citations to the employer.

    Return to the beginning.

    Investigation

    In an urban thoroughfare, the team was tasked with eliminating a deceased tree from the periphery of a residential road at the scene of the occurrence. The team members comprised of one temporary employee and one employee with a tree pruner I classification, along with two employees (the deceased and another worker) who possessed tree pruner II classifications. Two teams were allocated to collaborate for the entirety of the day within the city.

    The tree on the sidewalk extending north toward a home and the tree on the sidewalk extending south over the main street had three main branches. The tree was completely devoid of leaves and there were no leaves on the tree. The trunk had a diameter of 24 inches, with the base of the tree measuring 31 inches in diameter from the ground. The tree was located between the road and the pedestrian sidewalk. The dead silver maple tree needed to be removed.

    The crew arrived at the site at approximately 8:30 a.M. They had already removed at least two trees earlier in the morning. Upon arrival at the incident site, the decedent conducted a pre-job briefing with the crew. The decedent was responsible for all safety issues on the site and was in charge of the worksite. Traffic control was established and equipment was positioned as the operation began.

    Figure 2

    Figure 2. Overview of work site.

    Figure 2. Overview of work site.

    The crew took approximately two hours to remove the trunk, tree limbs, and brush. There were no unusual defects or abnormalities observed in the tree. The coworker who brushed out the tree noticed no defects. The Tree Trimmer II coworker used an aerial lift to prepare the tree for felling by removing all the smaller branches and limbs from the three main limbs.

    The deceased had decided that the southern branch, which was tilting towards a house, should be taken down as the first step.

    The safety technician from the city chose this position so that he would still be able to watch the work crew’s activities and be able to operate the friction rope, while being able to address any concerns or hazards related to pedestrians, vehicles, etc. He was standing in the street, about 25 feet away from the tree’s trunk, underneath the north side of the tree where the tree’s branches were not in the fall zone.

    The truck stake was lowered to see three figures, and as the limb was cut from it, the rope prevented it from uncontrollably swinging by providing friction. The tree trunk was used to stop the momentum of the falling limb, and the rope was wrapped around the tree trunk to secure the cut section for future use. To help control the cut section of the south limb, a clove hitch knot was used, and the south limb was cut into long sections, ranging from 5 to 8 feet, leaving a wood hinge to aid in controlling the fall. The decedent controlled the synthetic friction rope, which had a single diameter of 5/8 inch, as both a tag line and a load line.

    Figure 3

    Figure 3. Overview of worksite: trunk wrap, suspended limb.

    Figure 3. Overview of worksite: trunk wrap, suspended limb.

    The incident took place following the fourth slice. Upon finishing the fourth cut, the branch detached and swung down, hitting the side of the tree trunk. The team had employed this technique to eliminate three parts of the branch and had not faced any issues.

    It is hypothesized that the center tree limb, situated around 25-30 feet above the deceased individual, could have snapped off at a weakened area in the middle section. The vibrations of the tree may have led to the detachment of the center tree limb during the fourth cut. The descent of the limb resulted in the tree experiencing vibrations upon each impact.

    The coroner calculated the mass at 150 pounds and the safety specialist estimated it at 40-50 pounds. The appendage that hit the deceased was roughly five feet in length. It collided with the deceased on the right side of his head and shoulder, detaching from the central section of the limb and falling away from the tree. The observer saw the central section of the limb detach from the tree and descend while witnessing the deceased lower the limb. The witness noticed that the south limb struck the trunk of the tree.

    The limb, which was about half an inch thick, had completely lost its bark. The knothole was concealed by a nest built by a bird or squirrel, and it had decayed where the limb had snapped. The person who passed away was not aware of the limb falling from the tree, and the witness did not think they had enough time to alert the person. This is what the witness stated.

    Following the accident, he passed away around fourteen days later. An ambulance transferred him to a nearby hospital. The emergency response team arrived, and they repositioned the limb to ensure access for emergency response. The work crew turned him on his side to aid with breathing. Upon impact, the individual did not respond. The force of the limb hitting him propelled him into the air, causing his hard hat to be knocked off by the falling limb.

    Return to the beginning.

    Cause of Death

    The death certificate stated that the cause of death was craniocerebral trauma. No toxicological tests were conducted.

    Recommendations/Discussion

    Employers should evaluate tree-pruning operations and ascertain whether current rigging techniques could be enhanced with available technology.

    The crew used rigging techniques such as a clove hitch and wrapping the trunk to lower the limb to the ground. They started cutting sections of the limb, ranging from 5 to 8 feet, starting at the edge of the limb. This method was chosen to minimize the additional shock load on the ropes and the distance the limb would fall, in order to prevent the trunk of the tree from being struck and the branch from which the limb was falling to stop the momentum. However, the limb was dropped before the rigging caught it, resulting in a weight of approximately 2,500 pounds falling about four feet, with an additional 500 pounds of force from the unit’s weight.

    Employers should encourage employees to adequately train on new techniques for rigging and explore different rigging techniques in their respective areas.

    The government needs to implement stricter regulations to protect the environment. Output: The government should enforce more stringent rules to safeguard the ecosystem.

    It is not advisable for a member of an active work crew to also be accountable for the upkeep of site safety; the person in charge of site safety when work crews interact with the public should exclusively handle those responsibilities. The fact that he was positioned on the street suggests that he may not have effectively fulfilled both roles, as he was in a position where these two job responsibilities overlapped. In addition to being an active worker at the worksite, he had other responsibilities besides maintaining site safety for both the crew and the public spectators. A crowd of onlookers always gathers to observe the work being done, as is common with any city activity, and the individual in question was tasked with ensuring both crew safety and site safety.

    Employers should establish standardized work practices for safe tree trimming, which includes instructing employees to use an axe to handle dead tree limbs and prohibiting them from working under a tree with a dripping sap line.

    To safeguard against unforeseen tree fractures, employers should establish uniform protocols, such as forbidding employees from working beneath the canopy of a tree and inspecting branches to detect vulnerable areas.

    He chose his position in the street so he could maintain the safety of the work crew and observe the site. The decedent chose this position by selecting a path where other tree limbs were falling. The tree was dead, and there was a possibility of unobserved tree hazards. Although the decedent was outside the fall zone of the cut limb, he was within the canopy or “drip line” of other tree limbs that could potentially break and fall. It is always important to give special consideration to planning for hazardous trees or trees that may unexpectedly fall or act in a hazardous manner. This is emphasized in the “Safe Tree Felling Guide Pocket” from the National Arborist Association (NAA).

    Prior to cutting through any hollow sections, such as the tree’s limbs being taken down, a hammer or an ax handle should be used to identify any hollow areas.

    Return to the beginning.

    Resources

    The phone number for the MIOSHA Standard Section is (517) 322-1845. To obtain the Standards, you can write to the Michigan Department of Labor and Economic Growth, MIOSHA, MIOSHA Standards Section at P.O. Box 30643, Lansing, Michigan, 48909-8143. Alternatively, you can visit the MIOSHA website www.Michigan.Gov/mioshastandardsexternal icon or access the MIOSHA Standards mentioned in this report for a fee.

  • MIOSHA General Industry Safety Standard, Part 53, for Tree Trimming and Removal.
  • Chisholm, Mark J. Designing the Removal of a Tree. Tree Care Industry. April 2000. Pgs 24-27. Internet Address: www.Treebuzz.Com/pdf/treeremoval.Pdfpdf iconexternal icon.
  • Lilly, Sharon. Guide for Climbing Trees, 3rd Edition. International Society of Arboriculture. P.O. Box 3129, Champaign, IL 61826-3129. Website: www.Isa-arbor.Comexternal icon.
  • The National American Arborist Institute, located at 3129 Champaign, IL 61826-3129, follows the published safety requirements and operational standards for arboriculture set by the Arboricultural Society International. These standards are outlined in the ANSI A133.1-2006.
  • The address of Inc. Is 3 Perimeter Road, Unit 1, Manchester, NH 03103. The National Arborist Association, Inc. Holds the copyright for the year 2000. The NAA Pocket Guide, which is published by the National Arborist Association Inc., Provides information on safe tree felling. The Internet address for the guide is http://128.241.193.252/index.Aspx (Please note that the link was updated on 5/2/2007 and is no longer available as of 3/25/2013).
  • Gerstenberger, Peter. The “Z” Goes Through Changes. Tree Care Industry Association. Internet Address: http://128.241.193.252/index.Aspx (Link updated 5/2/2007 – no longer available 3/25/2013).
  • Michigan FACE Program

    On January 23, 2007, Michigan State University (MSU) reserved the rights to equal employer opportunity and affirmative-action. It is prohibited to use MSU as a platform to advertise or endorse any commercial company or product. However, the MIFACE report may be reprinted with credit given and upon publication, it becomes public property. This information is solely for educational purposes and is related to the Evaluation, Control, and Assessment of Fatality in the Environmental & Occupational Medicine department at MSU, located in East Lansing, Michigan, at West Fee Hall, Room 117.

    Please utilize the contact information listed on the NIOSH website for the FACE State-based personnel program in Michigan to obtain reports and assistance. In cases where you cannot reach personnel from the FACE State-based program, please refer to the contact information on the NIOSH website for the in-house personnel program in Michigan.

    Michigan Case Studies.