According to the report, before the derailment, an alarm instructed the crew to stop the train to inspect a hot axle, and an automatic emergency brake initiated.

The report indicates that after the train stopped, the crew observed smoke and fire and notified dispatch of a possible derailment. With dispatcher authorization, “the crew applied handbrakes to the two railcars at the head of the train, uncoupled the head-end locomotives, and moved the locomotives about 1 mile from the uncoupled railcars. Responders arrived at the derailment site and began response efforts,” the report states.

NTSB investigators identified and examined the first railcar to derail, which was the 23rd railcar. Surveillance video from a residence showed what appeared to be a wheel bearing in the “final stage of overheat failure” moments before the derailment.