Industrial Incident Investigation Techniques

Thomas V. Rodante, P.E., CFEI, CFII
Baker Engineering and Risk Consultants Inc., USA

Presented at International Symposium on Fire Investigation, 2012

NFPA 921 provides an excellent framework for individuals charged with the responsibility of investigating fire and explosion incidents. NFPA 921 establishes systematic investigative and analytical scientific techniques around the core principle of scientific methodology. Guidance is provided in NFPA 921 to show and explain the process of evidence collection, analysis, hypotheses formulation, forensic hypotheses testing, hypothesis correction and re-testing, and final cause determination. This presentation provides case study examples, not offered within NFPA 921, of forensic scientific methodology as applied to industrial petrochemical processing incidents.

Specific potential industrial evidence types are discussed and examples provided. The use of a timeline spreadsheet beyond that explained in NFPA 921 is shown with examples of how to correlate process data to witness statements. A case study scenario supposition and hypothesis spreadsheet is provided to show an example method for organizing observations, list related hypotheses, determine forensic test criteria, and document results. The provided example includes scientific forensic use of flame and vapor dispersion modeling, and metallurgical analysis. Finally, an example fault tree is shown as an alternative analytical method for cases in which the existence of physical evidence may be limited.

Download the complete paper here

October 7, 1871: Most Devastating Fire in US history

The most devastating fire in United States history is ignited in Wisconsin on October 7th, 1871. Over the course of the next day, 1,200 people lost their lives and 2 billion trees were consumed by flames. Despite the massive scale of the blaze, it was overshadowed by the Great Chicago Fire, which began the next day about 250 miles away.

Peshtigo, Wisconsin, was a company lumber and sawmill town owned by William Ogden that was home to what was then one of the largest wood-products factories in the United States. The summer of 1871 was particularly dry across the northern Midwest. Still, settlers continued to set fires, using the “slash and burn” method to create new farmland and, in the process, making the risk of forest fire substantial. In fact, the month before had seen significant fires burn from Canada to Iowa.

Peshtigo, like many Midwestern towns, was highly vulnerable to fire. Nearly every structure in town was a timber-framed building–prime fuel for a fire. In addition, the roads in and out of town were covered with saw dust and a key bridge was made of wood. This would allow a fire from outside the town to easily spread to Peshtigo and make escaping from a fire in the town difficult. On September 23, the town had stockpiled a large supply of water in case a nearby fire headed in Peshtigo’s direction. Still, they were not prepared for the size and speed of the October 7 blaze.

The blaze began at an unknown spot in the dense Wisconsin forest. It first spread to the small village of Sugar Bush, where every resident was killed. High winds then sent the 200-foot flames racing northeast toward the neighboring community of Peshtigo. Temperatures reached 2,000 degrees Fahrenheit, causing trees to literally explode in the flames.

On October 8, the fire reached Peshtigo without warning. Two hundred people died in a single tavern. Others fled to a nearby river, where several people died from drowning. Three people who sought refuge in a water tank boiled to death when the fire heated the tank. A mass grave of nearly 350 people was established because extensive burns made it impossible to identify the bodies.

Despite the fact that this was the worst fire in American history, newspaper headlines on subsequent days were dominated by the story of another devastating, though smaller, blaze: the Great Chicago Fire. Another fire in Michigan’s Upper Peninsula that consumed 2 million acres was an even smaller footnote in the next day’s papers.