This subrogation action arises from a fire that occurred on April 10, 2022, involving a dump truck owned by Boggs Transport, Inc. (“Boggs”) and insured by Plaintiff Amerisure Insurance Company (“Amerisure”).
The fire began in a parked dump truck identified as Truck No. 863 at Boggs’s facility in Pageland, South Carolina, and spread to four adjacent trucks, resulting in damage to five vehicles. At the time of the fire, Truck No. 863 had been upfitted with a tarping system manufactured and installed by Defendant and Third-Party Plaintiff Ox Bodies, Inc. (“Ox Bodies”). Amerisure, as subrogee of Boggs, initiated this action asserting claims against Ox Bodies arising from the alleged origin and cause of the fire. Ox Bodies denied liability and disputed both the location of the fire’s origin and the mechanism by which the fire ignited.
In support of its claims, Amerisure designated two expert witnesses. Kenny A. McClure, P.E., M.S.M.E., CFEI, is offered as an expert in fire origin. McClure opined that the fire originated along the driver’s side of Truck No. 863, in the area of the battery compartment and associated electrical components mounted along the frame rail. Kevin R. Davis, P.E., is offered as an expert in fire causation. Davis opined that the fire was caused by an electrical failure associated with components of the tarping system, including a relay or controller installed as part of the Ox Bodies upfit.
Ox Bodies filed a motion to exclude the testimony of both of Amerisure’s experts pursuant to Federal Rule of Evidence 702.
Fire Investigation Expert Witnesses
Kenny A. McClure, P.E., M.S.M.E., CFEI holds an Associate of Applied Science in mechanical engineering technology, a Bachelor of Science in engineering technology, a Master of Science in mechanical engineering, and designations as a licensed professional engineer, a certified fire explosion investigator, a certified fire vehicle investigator, and a certified fire and explosion investigator.
Kevin Ray Davis, P.E. holds a Bachelor of Science in Electrical Engineering, is a licensed professional engineer, and maintains professional certifications in fire and explosion investigation and vehicle fire investigation. He has also worked for more than fifteen years as a consulting engineer investigating fires and electrical failures.
Discussion by the Court
A. Kenny McClure
1. Reliability of the Origin Opinion
Defendant primarily argued that McClure’s testimony is unreliable because his defined origin area is allegedly inconsistent with Defendant’s expert’s electrical arcing theory.
Defendant framed the issue as a logical dilemma: if McClure’s origin area excluded the arcing location identified by Defendant’s expert, then McClure allegedly failed to consider an obvious alternative ignition source. Conversely, Defendant argued that if McClure’s origin area included that location, the opinion is unnecessary because both parties’ experts would be describing the same origin area. The Court did not find this argument persuasive because it conflates the geographic scope of an origin determination with the identification of a specific ignition source.
To begin with, McClure is offered as an origin expert, not a causation expert. His opinions concerned the location of the fire’s origin within Truck No. 863, not the specific mechanism of ignition. That distinction frames the Court’s Rule 702 analysis.
Fire investigators commonly identify an area of origin rather than a single ignition point when the available physical evidence does not permit greater precision. McClure applied this methodology here, concluding that the fire originated “along the driver’s side of Truck 863 in the area where the battery compartment, conductors, and electrical components are mounted along the frame rail.” That conclusion was based on his examination of burn patterns, fire dynamics, and electrical artifacts observed during the investigation. The record reflected that McClure employed the systematic fire-investigation methodology described in NFPA 921. Ox Bodies did not challenge the reliability of that methodology itself. Accordingly, the Court concluded that McClure’s origin analysis rests on a reliable investigative methodology consistent with Rule 702.
2. Defendant’s Relay-Knowledge Argument
Ox Bodies also argued that McClure’s opinion is speculative because he did not account for the post-fire location or condition of certain tarping-system relays.
The Court concluded that this argument improperly conflates origin analysis with ignition-source or causation analysis.
Under NFPA 921’s scientific method, investigators commonly determine the fire’s area of origin before identifying the specific ignition source. An investigator’s inability to determine the precise ignition mechanism does not invalidate the origin determination so long as the origin analysis is based on observed fire patterns, electrical artifacts, and other physical evidence.
Here, McClure’s testimony concerns the area where the fire began, not the precise electrical component that initiated it. Defendant’s criticisms regarding relay locations, therefore, go to the weight of the testimony rather than its admissibility.
3. Helpfulness to the Jury
Ox Bodies also contended that McClure’s origin opinion is so broad that it amounts to common knowledge and is unhelpful to the jury. The Court disagreed. Although the identified origin area is not confined to a single component, the opinion rests on specialized interpretation of burn patterns, electrical artifacts, and fire dynamics beyond the experience of lay jurors. Interpreting burn patterns, electrical damage, arc mapping artifacts, and other indicators of fire progression requires specialized training and experience. Jurors lack the technical background to interpret such evidence reliably without expert assistance.
Accordingly, the Court found that McClure’s origin opinions are grounded in accepted fire-investigation principles and satisfy Rule 702.
Kevin Davis
1. Reliability of Davis’ Methodology
Ox Bodies first argued that Davis’ opinions violated accepted fire-investigation methodology because he did not determine ignition temperature, quantify the duration of any electrical fault, or conduct testing to replicate the proposed ignition mechanism.
The Court agreed that portions of Davis’ analysis lack sufficient methodological support. Davis did not perform testing to confirm that the specific relay installed on Truck No. 863 could produce sufficient heat to ignite surrounding materials. Nor did he quantify the ignition temperature or duration necessary to produce ignition under the conditions present in the vehicle. Davis also relied in part on exemplar relay testing and recall information involving different relay configurations and applications.
Here, the record does not contain sufficient evidence connecting the exemplar relay testing or recall materials to the specific relay installed in Truck No. 863. Without testing, analysis, or other evidence showing that the relay in question was capable of generating sufficient heat to ignite the surrounding materials under the conditions present in the truck, the Court concluded that the methodology supporting Davis’ specific ignition-source opinion is insufficient under Rule 702.
2. Application of the Methodology to the Facts
The Court nevertheless found that Davis’ testimony is not wholly inadmissible. Davis’s report also included engineering analysis concerning the truck’s electrical system, including the condition of the wiring harness, the lack of circuit protection in portions of the tarp-system wiring, and the potential for energized conductors to create ignition sources within the electrical system.
These opinions are grounded in Davis’s inspection of the physical evidence and his application of electrical engineering principles to it. Such testimony may assist the jury in understanding the electrical mechanisms that could have produced a fire in the relevant portion of the vehicle.
Accordingly, Davis may testify regarding electrical fire mechanisms, wiring damage, circuit protection, and the potential for energized conductors to act as ignition sources within the electrical system of Truck No. 863. However, Davis may not opine that a specific relay or tarping-system component installed on Truck No. 863 was the ignition source of the fire.
This limited exclusion reflects the Court’s obligation under Rule 702 to ensure that expert testimony rests on a reliable foundation while permitting otherwise admissible technical testimony that may assist the trier of fact.
To the extent Davis discussed the circuit breaker during his deposition testimony, the Court found that those statements elaborate on the electrical-fault theory disclosed in his report and are not a new expert opinion requiring exclusion under Rule 26.
Held
- The Court denied Defendant and Third-Party Plaintiff Ox Bodies, Inc.’s motion to exclude the testimony of Kenny A. McClure, P.E., M.S.M.E., CFEI.
- The Court granted in part and denied in part Defendant and Third-Party Plaintiff Ox Bodies, Inc.’s motion to exclude the testimony of K.R. Davis, P.E.
Key Takeaway
Even assuming McClure’s origin area overlaps with the location proposed by Defendant’s expert, the testimony remains relevant and helpful because McClure explains the fire patterns, burn damage, and electrical artifacts that confine the fire’s origin to a particular structural portion of the vehicle. Such analysis assists the jury in understanding the physical evidence and does not become inadmissible simply because the parties’ experts may partially overlap in their conclusions.
Case Details:
| Case Caption: | American Insurance Company V. Ox Bodies, Inc |
| Docket Number: | 4:23cv2445 |
| Court Name: | United States District Court, South Carolina |
| Order Date: | March 17, 2026 |
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