The goal of “zero incidents” is an impossible standard. As a profession, we have promoted this concept, but it is simply not realistic. While safety is always a priority, arboriculture is performed in a high-hazard environment, and every day requires thousands of decisions with incomplete information. What does that tree part weigh? How much decay is present? How strong is that tie-in point (TIP)? Unfortunately, human beings are prone to mistakes – both mental and physical – and these mistakes sometimes result in property damage, injury or even death.

The author, far right, and his Tree133 team in a 2025 photo. All photos courtesy of Craig Bachmann.

In August 2022, Tree133 experienced a climber fall resulting in a severe injury. For a well-respected company owned by a recognized trainer, this was an unthinkable event that challenged everything we believed about ourselves and our company culture. The lessons from this event resulted in growth throughout the company, from changes in hiring practices to a more structured approach to training.

Most important, it forced us to accept that incidents cannot be entirely prevented – other than by staying home. Instead, we must take action to minimize the likelihood and severity of incidents at work.

The tree from incident.

The failed leader from the incident.

Self-assessment
At Tree133, we strive for excellence in everything we do. We are a small business that considers everyone to be part of our family. Each of our six field-team members is an ISA Certified Arborist, with most having the Tree Risk Assessment Qualification credential. One of our senior staff also earned TCIA’s Certified Treecare Safety Professional (CTSP) credential.

Our field team, not including the owner, has a combined 42 years of professional experience. We have a nice shop and office, high-quality tools and equipment and a team of exceptional people. And yet … we still had a near-fatal incident.

So, what happened that day in 2022, both in the tree and on the ground? How did we respond? And how did this experience change our approach to arboriculture?

The incident
On September 14, two Certified Arborists were tasked with risk-mitigation pruning of a European white birch (Betula pendula) roughly 45 feet in height at a private home in a city neighborhood of Seattle, Washington. This tree species is commonly damaged by the bronze birch borer insect that tends to leave it with large, unstable deadwood in the upper crown.

Risk-mitigation pruning of trees in this condition is a typical project for our team. The assigned arborists had a combined 17 years of professional experience, most of it in the Seattle area. Due to limited access, it was necessary to climb this tree. The work order specifically noted large deadwood and the need for caution when working aloft.

Upon arrival, the arborists met the property owner, reviewed the work order and then completed a Job Hazard Assessment, documenting the work location, site hazards, tree hazards, location of the nearest urgent-care facility and roles for emergency response. These arborists had worked together daily for more than a year. Both were strong climbers, and work on the birch was easily within their skills and comfort zone.

One arborist gathered his climbing gear and throwline and prepared to enter the tree. The other began a small pruning task elsewhere on the property, expecting to help with the birch when the climber was ready in the tree.

A few minutes later, while working at the side of the house, the arborist on the ground saw something in his peripheral vision and heard a thud. When the arborist on the ground turned, the climber was lying on the ground next to a picket fence. His climbing line was jumbled nearby, along with a broken part of the tree. The climber was moving and began to stand up. When asked if he was OK, he said, “Yes, I think so.” He walked to the front steps of the home and sat down.

The new procedure: A pre-climb inspection by two arborists.

What happened?
As described by the climber, he had set an initial TIP from the ground. While advancing higher in the tree, he noticed a nest (type unknown) in a major union. To avoid disturbing the nest, he set his climbing line through a branch union partway up a 7-inch-diameter, angled leader. After releasing his lanyard and beginning to move upward, the leader failed mid stem, resulting in a 25-foot ground fall.

Upon later inspection, the leader was obviously dead and substantially deteriorated. After the fall, the climber stood up under his own power, and the journey to urgent care and to the hospital began.

After brief discussion, the two arborists felt the situation was not life threatening and called the company office to notify them of the incident. The climber mentioned pain in his lower back and was transported to urgent care in a company vehicle, while the second arborist packed up the work site and drove the chip truck back to the shop. Upon arrival at urgent care, and due to the complaint of back pain, the climber was placed on a backboard and transported by ambulance to the hospital, where multiple spinal fractures were diagnosed.

Reportable injury
Due to the required hospitalization, this was a “reportable injury,” which triggered a state-level OSHA investigation. While details of that investigation are beyond the scope of this article, a few points are worth mentioning.

First, the investigator was very professional but knew exactly nothing about arboriculture. It was up to us to “educate” him about safety standards and operating procedures for professional tree climbing. Second, the investigation process required that we (the company) prove our diligence in training and provide documentation to support that we had adequately prepared the team for every aspect of their work. And finally, the investigation found Tree133 failed to have a “Fall Protection Work Plan” in place for the job.

It turns out this “Fall Protection Work Plan” is a document from the construction trades to put on record safety procedures – such as anchorage and type of fall protection required – for any job requiring work at height. While this outcome challenged us to upgrade our JHA documentation, it frankly did nothing to help us understand the causes of the incident. On the bright side, we received only an “other-than-serious citation” for lack of paperwork without a financial penalty.

Jumping ahead, the climber was out of work or on light duty for a total of six months. He did not need extended hospitalization, and within a few months was cleared to return to work as a climbing arborist. This person has since left the area for family reasons, and we wish him the best in his new adventures.

A climber advancing his tie-in point
(TIP).

Assessment
On one hand, this is a success story. We are all deeply grateful for the climber’s full recovery and the absence of a life-altering injury. From another perspective, that of a business owner and safety manager, this incident is terrifying.

If the climber had fallen 24 inches to one side, he would have landed directly on a picket fence, and the outcome would be entirely different – likely a debilitating injury or even a fatality. Only by dumb luck were these outcomes avoided. And if an incident this serious can happen to knowledgeable arborists with 17 years of professional experience, something similar could happen on any tree crew and at any company. This realization was really the beginning of our learning process.

Through our internal incident review and discussions with the arborists involved, we identified several factors that increased the likelihood of an incident and could have exacerbated the injury. For the climber aloft, he acknowledged being distracted by the nest and failing to adequately assess his new TIP before committing to it. We also recognized this climber had a high personal tolerance for risk.

As a former collegiate athlete and active outdoorsman, he was incredibly strong and enjoyed testing his limits in his recreational activities. This attitude carried over into his work and may have led to overconfidence and a feeling of invincibility. After the incident, we observed the JHA had been completed by the climber, and he had rated the hazards associated with tree structure and condition to be low, despite the obvious large deadwood and sensitive climbing that would be required in the upper crown. While most arborists would approach this tree with extra caution, the under-rating of the hazard suggests the climber felt confident and unconcerned about the work required.

Perception and awareness
On the job site, the second arborist did not witness the fall and was not aware of the actual height (25 feet) until much later. He assumed the TIP broke as the climber was beginning to ascend and was only a few feet off the ground. He relied on the climber’s perception of his own condition and did not call 911 for emergency medical assistance. Looking back, he felt their response to the incident may have been different with better communication.

Another possible factor is the perception of calling 911. While emergency response protocols state this action as necessary and automatic, they do not consider the potential psychological obstacles. Arborists pride themselves on being resourceful and solving problems. Calling 911 acknowledges that something has gone terribly wrong, and taking that action may be perceived as acknowledging defeat.

We also recognized that aspects of our company culture may have inadvertently contributed to the incident. Tree133 is a small company that intentionally hires skilled arborists. As a growing business with intense demands on the owner, we delegated many responsibilities to our field team and emphasized personal responsibility. In retrospect, this led to assumptions about individual skills and knowledge, as well as a lack of awareness on how decisions were made on the job and specifically while working aloft. In retrospect, this resulted in a safety program that was well intentioned but perilously informal.

In total, this incident exposed weaknesses in our company culture, our training and our emergency response, and led to significant changes in how we approach the business of arboriculture.

Changes
First, we changed our perspective on the role of the business owner and field supervisor. Rather than focusing on sales, production and quality, we are first and foremost risk managers. Every decision either reduces or increases risk, from who we hire and how we train skills and assess competency to how we estimate time and resources for a job. We must constantly consider the risk exposure to our team and our company.

Second, we have begun an effort to train, assess and document the knowledge and skills required for every aspect of work by our field team, and our office staff, too. Assuming what a team member knows can be catastrophic. Thinking specifically about climbing skills, we are working toward training and assessing each component skill, such as pre-climb inspection, species failure profiles, tie-in-point (TIP) selection, techniques for rope advancement, work positioning on MRS and SRS systems, aerial-cutting techniques, rigging methods and much more.

As the owner of a small business, this objective often feels ludicrously complex and unachievable, and it will take years to reach the ultimate goal. But we must start somewhere, and we must clearly document each person’s skillset. Failing to identify gaps in the knowledge and skills of our team puts everyone at risk. And when an incident happens, only proper training and thorough documentation will protect your team and your company.

Consensus and communication
We also upgraded our pre-climb inspection. Beyond the standard inspection for electrical hazards, tree health, structural defects, decay fungi, etc., we have added the concept of consensus tie-in points. As they say, two heads are better than one. We require two arborists to look at each tree and discuss appropriate TIPs for initial access and final work positioning. Regardless of individual experience, the intention is to have a brief, constructive discussion about tree condition and the work plan. By openly sharing observations and knowledge, we can minimize risk to the climber. The key results are greater awareness of tree condition, attentiveness to species characteristics and better overall decision-making.

The incident highlighted a need for better communication during our response, specifically around when to call 911. We incorporated a decision-making concept from emergency medicine to help guide us. The mechanism of injury (MOI) is how an injury occurs and what part of the body is affected. For example, injuries to the torso, head/neck, upper arms and upper legs are more likely to cause a life-threatening situation compared to impacts to an extremity (e.g., lower arm, lower leg, hand or foot). And incidents involving significant energy, such as a fall from above 6 feet, heavy weight, high speed or electricity, have a greater potential to cause a life-threatening injury.

We now use MOI to help identify when an incident may cause a life-threatening (or life-altering) injury. When an incident includes a significant MOI, calling 911 is required. We also stress that none of our team is qualified to determine that an injured person “will be OK.” An injured person’s condition can quickly deteriorate, and they must be promptly evaluated by qualified medical personnel.

The Tree133 team in EHAP training.

Big picture
The items above are focused on policy and process; what we do and how we do it. But this incident also taught us big-picture lessons.

For example, it challenged us to reconsider our risk tolerance, both as a company and as individual arborists. We have come to believe that the tendency of climbers to behave as solo performers – meaning someone who “makes it happen” and willingly accepts significant personal risk in pursuit of that goal – is highly dangerous and undermines team safety. Yes, it is true that a climber must operate in an environment with specific and unavoidable hazards that are different from the team on the ground. However, every climber must recognize that his or her decisions impact the team and the entire company.

This incident taught us that the consequences of a climber’s mistake go far beyond personal injury and can alter the lives – and livelihoods – of the entire team. Everyone must take seriously their responsibility to one another and recognize that success – or failure – is achieved as a team rather than by individuals.

This led us to reconsider our hiring approach and to actively prioritize character and attitude toward others over skillset and years of experience. Yes, Tree133 still hires skilled arborists, but we also believe skill and knowledge can be taught, while empathy and a desire to be connected to others cannot.

We have implemented a process of candidate interviews with the business owner, office personnel and our field supervisor. Then, we conduct a “work with” day for our field team to evaluate the candidate’s fit with our company culture. We ask each team member to provide their feedback. And we have a policy to not hire any candidate over the objection of a team member.

Finally, this incident challenged me, the business owner, to become more involved with the field team. While our field supervisor is directly responsible for safety and training, it is my role to continually reinforce the culture of our company, specifically our three core values of excellence, respect and positive influence. I take responsibility for the incident in August 2022. While I was not on site that day, I created the organization and culture that allowed this to happen.

Conclusion
After two years’ reflection on this experience, I still firmly believe that “zero incidents” is an impossible standard. Humans are fallible. We make mistakes every day. To balance this, we must cultivate open communication, share close calls and prioritize continuous learning. We must hire people who care about others and want to be part of this culture. Through these actions, we will minimize the likelihood and severity of future incidents.

Craig Bachmann is a Board Certified Master Arborist (BCMA), Tree Risk Assessment Qualification (TRAQ) credentialed, an
experienced safety/skills trainer and lead arborist and founder of Tree133, a tree-preservation company and a five-year TCIA member company based in Seattle, Wash. He also is a member of the TCI Magazine Editorial Advisory Committee.

This article is based on his presentation on the same subject during TCI EXPO ’24 in Baltimore, Maryland. To view a recording created for that presentation, Click here.