Washington State safety officials are warning employers and workers in the tree care and landscaping industries to strengthen fall protection and rigging practices following a recent increase in worker deaths. A new hazard alert issued in mid-October by the Washington State Department of Labor & Industries (L&I) reports that 11 landscaping workers in the state died between 2020 and 2024, most while performing tree-trimming tasks. Nationwide, 228 landscaping workers were killed in 2023, according to the U.S. Bureau of Labor Statistics, underscoring the high-risk nature of the industry.

The “Tree Trimmer Hazard Alert” outlines several fatal incidents and identifies recurring safety failures that contributed to the deaths. Among them were climbers who accidentally cut their lifelines, workers struck by falling branches and rigging failures during lowering operations. In one case, a worker climbing a 120-foot Douglas fir inadvertently severed his flip line while cutting limbs and fell to the ground. In another, a trimmer was fatally struck by a suspended branch that broke unexpectedly. A third incident involved a shock load when a crew wrapped a lowering rope directly around a tree instead of using proper rigging equipment, causing the rope to whip upward and pull the climber from the trunk.

According to the alert, these tragedies highlight the need for pre-job hazard assessments, qualified supervision and the exclusive use of arborist-grade ropes, harnesses and rigging systems. L&I recommends that all tree work be overseen by a TCIA Certified Treecare Safety Professional (CTSP) or an ISA Certified Arborist who can evaluate job-site hazards and ensure compliance with ANSI Z133-2017 safety standards. Workers should receive training on safe climbing techniques, emergency descent procedures, communication protocols and rescue planning. Employers also are encouraged to conduct post-incident reviews to identify root causes and improve safety practices.

State safety officials stress that proper planning and equipment selection can prevent future fatalities. Even experienced climbers, they note, can make critical errors under pressure if protocols are not followed or equipment is improperly used. The hazard alert urges companies to treat tree trimming as a highly technical operation requiring formal safety management and supervision, not as routine groundskeeping work.

Tree trimming remains one of the most dangerous jobs in the United States, combining fall hazards, struck-by risks and electrical exposure. L&I’s latest alert serves as a reminder that comprehensive safety planning – supported by qualified leadership and continuous training – is the most effective defense against deadly incidents in the field.

To view the full alert, go to the digital version of this article online at tcimag.tcia.org and click this link: Preventing Tree Trimmer Deaths (PDF)

Stasia DeMarco is the content editor for OH&S Occupational Health & Safety magazine.