Saturday Technical Program
- 6:30 AM - Breakfast and Networking
- 7:15 AM - Opening and Attendee Introductions
- 8:00 AM - Morning Track
- Ziad Azzi, PhD, PE (NAFE #1343M) — “Discerning Wind-Related Damage to Residential Roofs: A Case Study of Shingle and Tile Roofs”
- Tonja Koob Marking, PhD, PE (NAFE #1152S) — “Forensic Hydraulic Analysis of a Tow and Barge Vessel Allision with a Lock and Dam”
- Michael Stall, PE (NAFE #955M) — “Forensic Engineering Evaluation and Quantification of Fire Damage to a Home Under Construction”
- Joseph Ellington, PE (NAFE #1332A) — “Artificial Intelligence and Fire/Explosion Investigations”
- 12:15 PM - Lunch
- 1:15 PM - Afternoon Track
- Henry Mowry, PE (NAFE #1195M) and David Ridder — “The Importance of Human Perception in Incident Reconstruction and the Potential for Misleading Interactive Reconstructions”
- Robert Peruzzi, PhD, PE (NAFE #967M) — “Forensic Investigation of Bitcoin Mining, Power Transmission, and Vegetation Mismanagement Causing Electrical Faults and Railroad Control System Failures”
- Stephen Batzer, PhD, PE (NAFE #677F) — “Barrel Failure in an Over and Under Shotgun”
- Samuel Stoll (NAFE #1318M) — “Legacy Lines, Latent Flaws: Looking at a Pipeline Disaster Through a Forensic Lens”
- 5:30 PM – Lobby Bar Meetup and Dinner on Your Own
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Discerning Wind-Related Damage to Residential Roofs: A Case Study of Shingle and Tile Roofs
Ziad Azzi, PhD, PE – Director of Engineering, DDA Forensics
Time: 8:00–9:00 AM
Abstract:
Hurricane season brings a significant rise in wind-related insurance claims, as powerful storms lead to property damage (particularly to roofs). The surge in claims places pressure on insurance carriers, leading to delays in processing or disputes over claim validity. Distinguishing between wind- and nonwind-related damage as well as pre-existing issues to roofing components becomes critical in ensuring fair, efficient, and timely resolutions. This study presents an in-depth analysis of wind-related damage to two common roof covering materials: asphalt composition shingles and clay/concrete tiles. Utilizing a series of detailed case studies coupled with data from field inspections, this paper aims to differentiate wind-induced damage to roofs from issues stemming from wear and tear, material aging, and installation deficiencies, among other environmental and mechanical factors. By examining damage patterns, damage location, and material behavior from field observations — coupled with wind flow around bluff-bodies such as residential structures — this paper highlights how the unique properties of each roof (including its location, height, shape, and slope) influence its response to wind-induced pressures during extreme wind events. The insights aim to enhance damage identification, including cause, origin, and duration of roof covering failures as well as support informed decision making for roof inspectors.
Bio: Dr. Azzi is a civil and structural engineer specializing in wind and building enclosure systems. He teaches at the University of Miami and leads engineering at DDA Forensics.
Forensic Hydraulic Analysis of a Tow and Barge Vessel Allision with a Lock and Dam
Tonja Koob Marking, PhD, PE – Owner and President, Gaea Consultants, LLC
Time: 9:00–10:00 AM
Abstract:
During record-high water on a major river, a tow pushing 14 barges allided with a lock and dam structure. Detached barges allided with gates, making two inoperable and damaging three others. Multiple structures in the adjacent town flooded as the earthen levee overtopped when the pool level rose in response to the inoperable and damaged gates. Recreation of river conditions utilizing hydraulic gages revealed gate opening and closing operations counter to the official incident report. As-built drawings reconciled with real-time photographs demonstrated actual gate openings were not as testified by lock personnel or reported in the official inquiry. Cell phone logs, videos, and vessel tracking and voice data were instrumental in recreating navigational instructions and responses during the vessel transit. The opposing expert’s computer modeling illustrated the velocity field prior to the allision, further supporting the forensic hydraulic analysis and questioning official claims regarding the root cause of the incident.
Bio: Dr. Koob Marking is a licensed PE with 30+ years in hydraulic engineering and expert witness work. She leads Gaea Consultants and formerly worked with the U.S. Army Corps of Engineers.
Forensic Engineering Evaluation and Quantification of Fire Damage to a Home Under Construction
Michael Stall, PE – President, Managed Response, Inc.
Time: 10:15–11:15 AM
Abstract:
When construction of an 8,000-square-foot custom home was close to completion, a fire started when a torch-down type of modified roof was being installed. The fire started at the west end of the 150-foot-long building, and the heat damage and smoke contamination traveled to the east end through the attic, the second floor, and the first floor ceiling cavity. Detailed forensic evaluation found heat damage and smoke residue throughout the building in exposed and hidden areas. Since the smoke residue can leave behind contaminants that have negative health effects on occupants — and this was a new home under construction — it was imperative to identify all contaminated building components. This paper examines the forensic engineering evaluation processes and techniques that were utilized to identify the structural damage caused by the fire, the heat-damaged components such as the spray poly foam insulation, the asphaltic waterproofing membranes and plastic trim, and the smoke-contaminated building materials and other components that must be removed to provide a new home condition.
Bio: Michael Stall is a PE and DFE with over 45 years in construction and engineering. He specializes in damage evaluation and property insurance disputes.
Artificial Intelligence and Fire/Explosion Investigations
Joseph Ellington, PE – Consultant, FireLogix
Time: 11:15 AM–12:15 PM
Abstract:
This paper explores the integration of artificial intelligence (AI) in fire investigation, emphasizing its potential to enhance investigative processes and fire safety. AI can process large data sets, detect patterns, and assist in real-time monitoring, evidence analysis, fire pattern analysis, and predictive modeling. Despite its benefits, AI’s adoption requires caution due to potential biases and ethical concerns. NFPA 921 and NFPA 1033 (the standards for fire investigation) currently do not include AI but recognize its potential impact. Case studies illustrate AI’s application in fire scenarios, highlighting both successes and limitations. The paper will stress the importance of human expertise alongside AI, advocating for transparency and ethical use. It concludes that while AI offers significant advancements, it must align with industry, legal, and ethical standards to be effective and credible.
Bio: Joseph Ellington is a certified fire and explosion investigator with 40+ years of experience in fire dynamics and expert testimony.
The Importance of Human Perception in Incident Reconstruction and the Potential for Misleading Interactive Reconstructions
Henry Mowry, PE – Vice President of Engineering, Knott Laboratory
David Ridder – Forensic Visualization Expert, Knott Laboratory
Time: 1:15–2:15 PM
Abstract:
A common and key component to forensic engineering and incident investigations is the “reconstruction” component of the investigation. Reconstructions allow the investigator to build and analyze the incident based upon objective information, such as video cameras (including dash cameras, surveillance cameras, and more), post-incident photographs (such as from first responders, eyewitnesses, etc.), physical data, including things such as skid marks in a roadway, damage patterns to involved objects (e.g., vehicles, buildings, etc.), and even physical injuries. As reconstructions, software, and technology advance, “interactive” reconstructions are becoming more and more popular, allowing the reconstructionist to control and adjust the reconstruction as it is shown. Interactive reconstructions allow the controlling individual to move cameras, start and stop the reconstruction, adjust parameters or variables, and allow analysis of the incident from static and omniscient perspectives. However, such interactive reconstructions also have the potential to be misleading. This paper will discuss the often disregarded or misrepresented portion of a reconstruction — that is, what the individual(s) in question “saw” or “perceived” during the incident as well as demonstrate the potential for harm or misleading interactive reconstructions.
Bio: Henry Mowry is a mechanical PE with experience in liability and failure investigations. David Ridder creates forensic 3D reconstructions used in legal proceedings.
Forensic Investigation of Bitcoin Mining, Power Transmission, and Vegetation Mismanagement Causing Electrical Faults and Railroad Control System Failures
Robert Peruzzi, PhD, PE – President and Founder, R. Peruzzi Consulting, Inc.
Time: 2:15–3:15 PM
Abstract:
This paper analyzes the engineering failures that led to a legal dispute involving Bitcoin mining, electric power transmission, and railway safety. To support their high-energy operations, Bitcoin entrepreneurs purchased an idle power plant, its 135kV transmission line, and a right-of-way along railroad tracks. However, their failure to maintain vegetation along the transmission corridor — despite regulatory obligations — led to a severe electrical fault. A tree branch made contact with the transmission line, causing fault current to travel through the tree, into the ground, and along adjacent railroad tracks. This surge disrupted a microprocessor-controlled railroad crossing system, which activated its failsafe mode and closed the crossing, disrupting both freight and passenger rail services. The railroad operator, responding to municipal complaints, held the transmission line owners accountable and demanded corrective action. However, vegetation management efforts were insufficient, leading to recurring outages and legal action. This article presents a forensic engineering analysis of the event, examining fault current propagation, compliance with NFPA 70 (the National Electrical Code), and industry standards for vegetation management. Additionally, it highlights the forensic engineer’s role in investigating failures, preparing expert reports, and testifying in legal proceedings. The case underscores the risks of inadequate infrastructure maintenance and the cascading failures it can trigger.
Bio: Robert Peruzzi is an electrical engineer and forensic consultant with a background in microelectronics and expert witness services.
Barrel Failure in an Over and Under Shotgun
Stephen Batzer, PhD, PE – President, Batzer Engineering
Time: 3:30–4:30 PM
Abstract:
A 12-gauge over-and-under shotgun experienced a rupture in its lower barrel when firing standard factory ammunition. This incident marked the shotgun’s first use in the field, as it had only been test-fired at the factory with regular-pressure shells (not proof loads) prior to this event. The barrel steel split axially ahead of the reinforced chamber, under the polymer fore-end, causing hot gases and plastic debris to violently strike the shooter’s left hand, resulting in serious injury. A detailed metallurgical and geometric evaluation of the affected barrel was conducted at an independent third-party laboratory. Chemical analysis confirmed the steel matched SAE 1045 alloy with appropriate hardness for the barrel’s intended thickness. Performance testing on a new, identical shotgun using intentionally overloaded shells was also carried out, despite the spent hulls from the incident showing no signs of excessive pressure. The assessment uncovered a distinct manufacturing flaw in the lower barrel that had created a localized weak spot in the barrel wall.
Bio: Dr. Batzer is a mechanical forensic engineer, firearms expert, and frequent trial witness. He’s published 70+ technical papers.
Legacy Lines, Latent Flaws: Looking at a Pipeline Disaster Through a Forensic Lens
Samuel Stoll, EIT
Time: 4:30–5:30 PM
Abstract:
The 2010 gas pipeline explosion in a U.S. residential neighborhood remains a key forensic engineering case study. The transmission pipeline ruptured due to high hoop stress, accumulated fatigue, and stress concentration at a substandard longitudinal seam weld. By selecting ill-suited assessment methods like external corrosion direct assessment, relying upon insufficient traceable, verifiable, and complete (TV&C) records — and neglecting pipeline degradation of the time-dependent threat — the operator failed to prevent the rupture. The “grandfather clause” also exempted the pipeline from hydrostatic testing at 1.25 times the maximum allowable operating pressure to stabilize manufacturing and construction threats like longitudinal weld defects. The tragedy underscores the need for TV&C records, assessment methodologies addressing all potential threats, and strong regulatory frameworks. Forensic engineers must look beyond existing standards and consider the underlying limitations of engineering practices, such as risk assessments and inspection techniques, to prevent future incidents.
Bio: Sam Stoll is an EIT in Missouri with experience in gas pipeline safety, finite element analysis, and nondestructive evaluation.