Source EP1. National Transportation Safety Board, Preliminary Report RRD23MR005, issued February 23, 2023. Excerpts below are from the original publicly issued preliminary report; page numbers refer to PDF pages. This preliminary report is the sole blind evidence packet. Its findings are subject to change.

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Issued: February 23, 2023 Preliminary Report RRD23MR005
This information is preliminary and subject to change.
On February 3, 2023, about 8:54 p.m. local time, eastbound Norfolk Southern Railway (NS) general merchandise freight train 32N derailed 38 railcars on main track 1 of the NS Fort Wayne Line of the Keystone Division in East Palestine, Ohio.
The derailed equipment included 11 tank cars carrying hazardous materials that subsequently ignited, fueling fires that damaged an additional 12 non-derailed railcars. First responders implemented a 1-mile evacuation zone surrounding the derailment site that affected up to 2,000 residents. There were no reported fatalities or injuries.

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Train 32N comprised 2 head-end locomotives, 149 railcars, and 1 distributed power locomotive located between railcars 109 and 110. The consist included 20 placarded hazardous materials tank cars transporting combustible liquids, flammable liquids, and flammable gas, including vinyl chloride.
Train 32N was traveling about 47 mph at the time of the derailment, which was less than the maximum authorized timetable speed of 50 mph.
Vinyl chloride is a flammable petrochemical used in the manufacture of polymer polyvinyl chloride, or PVC. When exposed to heat, vinyl chloride can undergo a rapid polymerization reaction, an exothermic chemical process that can pose an explosion hazard.
Train 32N was operating with a dynamic brake application as the train passed a wayside defect detector on the east side of Palestine, Ohio, at milepost (MP) 49.81.

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The wayside defect detector, or hot bearing detector (HBD), transmitted a critical audible alarm message instructing the crew to slow and stop the train to inspect a hot axle. The train engineer increased the dynamic brake application to further slow and stop the train. During this deceleration, an automatic emergency brake application initiated, and train 32N came to a stop.
Train 32N passed three HBD systems on its trip before the derailment. At MP 79.9, the suspect bearing from the 23rd car had a recorded temperature of 38°F above ambient temperature. When train 32N passed the next HBD, at MP 69.01, the bearing’s recorded temperature was 103°F above ambient. The third HBD, at MP 49.81, recorded the suspect bearing’s temperature at 253°F above ambient. NS has established the following HBD alarm thresholds (above ambient temperature) and criteria for bearings:
Between 170°F and 200°F, warm bearing (non-critical); stop and inspect
A difference between bearings on the same axle greater than or equal to 115°F (non-critical); stop and inspect
Greater than 200°F (critical); set out railcar
After the train stopped, the crew observed fire and smoke and notified the Cleveland East dispatcher of a possible derailment.
On February 5, responders mitigated the fire, but five derailed DOT-105 specification tank cars (railcars 28–31 and 55) carrying 115,580 gallons of vinyl chloride continued to concern authorities because the temperature inside one tank car was still rising. This increase in temperature suggested that the vinyl chloride was undergoing a polymerization reaction, which could pose an explosion hazard. Responders scheduled a controlled venting of the five vinyl chloride tank cars to release and burn the vinyl chloride, expanded the evacuation zone to a 1-mile by 2- mile area, and dug ditches to contain released vinyl chloride liquid while it vaporized and burned. The controlled venting began about 4:40 p.m. on February 6 and continued for several hours.

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Surveillance video from a local residence showed what appeared to be a wheel bearing in the final stage of overheat failure moments before the derailment. The wheel bearing and affected wheelset have been collected as evidence and will be examined by the NTSB.
The NTSB’s investigation is ongoing. Future investigative activity will focus on the wheelset and bearing; tank car design and derailment damage; a review of the accident response, including the venting and burning of the vinyl chloride; railcar design and maintenance procedures and practices; NS use of wayside defect detectors; and NS railcar inspection practices.
The NTSB is not involved in air monitoring, testing of water quality, environmental remediation, or evacuation orders. Questions on environmental issues should be referred to the Environmental Protection Agency.
