December 4, 2023 | Susan Napier-Sewell

Falling Tree Fatality Investigation Report

falling tree fatality

This lesson learned concerns the investigation of a falling tree fatality that occurred during tree limb removal.

On August 14, 2023, Juston K. Fontaine, Deputy Director for Operations, Office of Science, U.S. Department of Energy, appointed an Accident Investigation Board Chairperson with the charge to assemble a team and investigate a falling tree fatality that occurred during tree limb removal activities on the Oak Ridge Reservation on August 11, 2023.

Due to the seriousness of the event and the injuries sustained by the individual, the appointment memorandum charged the Board to conduct the accident investigation in accordance with DOE Order 225.1B, Accident Investigations.

The report is also available via the DOE Accident Prevention and Investigation Program Website at:

The falling tree fatality details

On Friday, August 11, 2023, two Cortese/Davey employees were trimming trees and cutting down a large dead limb from a Scarlet Oak tree located just outside the perimeter fence line of the Lindsay-Bleu (Gallaher) cemetery located within the Oak Ridge Reservation (ORR). The Cortese/Davey crew made the final cut to the base of the 57-foot dead limb. When the final cut was made, the dead limb base struck the ground and the top made contact with other trees resulting in the top part of the dead limb breaking into two pieces.

Based on physical evidence and interviews, the 10-foot section of the dead tree limb fell towards the ground and struck the helmet of the Cortese/Davey worker, who was making the cut, splitting the safety helmet being worn at the time. The injured Cortese/Davey worker fell onto their left side unconscious.

The injured worker was initially transported to Oak Ridge Methodist Medical Center and was subsequently airlifted to the University of Tennessee Medical Center (Level 1 Trauma Center) where they later succumbed to their injuries.

On August 14, 2023, the U.S. Department of Energy (DOE), Office of Science (SC), Deputy Director for Operations (DDO) appointed a DOE Accident Investigation Board (AIB or Board) Chairperson to assemble a team to investigate the event to determine the facts and circumstances related to the event and identify possible weaknesses and opportunities for improvement related to implementation of Integrated Safety Management (ISM) principles.

The objective was to analyze the event and determine direct, root, and contributing causes, and from these provide Conclusions (CON) and Judgments of Need (JON). The Board was faced with certain obstacles in the conduct of the investigation. Specifically, as the investigation progressed, Davey declined to allow personnel interviews by the Board, including one who, being in close proximity to the accident, witnessed it. This limited the Board’s ability to evaluate human performance aspects of the event as well as obtain other highly relevant accounts, including an additional eyewitness statement, addressing the circumstances and sequence of events before and during the accident. As a result, certain details provided in this report regarding the event are considered as most likely based on the Board’s analysis of available documentation and interviews with other personnel. Unrelated to the event, a change to the DOE Prime Contractor for performing road and grounds maintenance, held by the incumbent contractor at the time of the accident, transitioned to a new contractor shortly after the accident occurred.

The Board determined the two Root Causes of the accident were:

RC-1: The prime contractor work planning and control lacked a disciplined and rigorous review process to ensure subcontracted work adequately defined the scope of work, identified and analyzed the hazards, and implemented the controls necessary to mitigate the associated risks.

Tree Felling Fatality at the Oak Ridge Reservation iv RC-2: The prime contractor and subcontractor failed to adequately communicate known hazards and risks associated with the work, and ensure mitigation measures commensurate with the risk, were in place and understood by those responsible to execute the work.

The root causes and the causal factors, if corrected, would prevent recurrence of the same or similar accidents, and address the charge elements assigned to the Board. The Board identified five JONs noted below representing improvements, that if fully considered beyond the short term, will provide the necessary foundation for the DOE OSO and its ORR contractors and subcontractors to build upon, to reduce the potential for recurrence of similar events. The CONs and JONs are documented in Section 5.0 of this report. JON-1: The prime contractor needs to ensure a work planning and control program is established and capable of producing safe and effective work control procedures. JON-2: OSO needs to ensure prime contractors have established a work planning and control program. JON-3: OSO needs to ensure all contractual and work requirements are properly identified and flowed down to prime and subcontractors. JON-4: Prime contractors need to ensure all contractual and work requirements are properly identified and flowed down to subcontractors. JON-5: OSO needs to clearly define R2A2s for safety and work planning control oversight of Reservation Management activities.

Content source/credit: Office of Environment, Health, Safety and Security, “Accident Investigation of the August 11, 2023, Tree Felling Fatality at the Oak Ridge Reservation,” published November 14, 2023.


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