Nearly three weeks after the East Palestine train derailment, a preliminary report on the incident has been released. The National Transportation Safety Board report details the Feb. 3 derailment of 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.Five of the derailed train cars were carrying 115,580 gallons of vinyl chloride, according to the report.Those five cars "continued to concern authorities because the temperature inside one tank car was still rising," indicating a polymerization reaction which could result in an explosion, the report said.READ THE REPORT HERE “I can tell you this much — this was 100 percent preventable,” said NTSB Chairwoman Jennifer Homendy. “We call things accidents. There is no accident.” NTSB said the train was traveling about 47 mph at the time of the derailment, which was less than the maximum speed limit of 50 mph. Train movements near the derailment site are authorized by cab signals and wayside signal indications with an overlaid positive train control system. The report said the positive train control system was enabled and operating at the time.The engineer operating the Norfolk Southern train applied additional brakes to stop it after receiving an alert of an overheating axle, the National Transportation Safety Board said in a preliminary report Thursday.The temperature reached a "critical" level — 253 degrees Fahrenheit above ambient temperature — and an audible alarm instructed "the crew to slow and stop the train to inspect a hot axle," the report states.The engineer had already applied the train's brakes and applied increased braking after the alert. The emergency brakes automatically applied, too, the NTSB said.Investigators say it was the 23rd railcar that derailed first because of that overheated wheel bearing. After the train stopped, the report said the train crew observed fire and smoke and notified the 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. Among the questions: Why wasn't the crew given a warning before the wheel bearing reached that critical temperature?“The warning threshold is set by railroads. It varies by railroad," Homendy said. "We're going to look at that and determine if that threshold should change. That's going to be one of our priorities in this investigation."CNN contributed to this report.