"I can tell you this much: This was 100 percent preventable. We call things, accidents. There is no accident. Every single event we investigate is preventable," Homendy said. However, she quickly added that there was no evidence that the train crew had done anything wrong.
The NTSB's preliminary report on the disaster disclosed that the temperature of one of the train's wheel bearings reached 215 degrees Fahrenheit over the last 30 miles it traveled. This was verified by the two sensors installed along the route used to detect hot bearings.
While Norfolk Southern confirmed on Thursday that the heat sensors were working well, the train's own alarm was not fixed to go off until an even higher temperature was reached.
By the time the alert sounded, the bearing was 253 degrees hotter than its environment. And while the engineer immediately acted to slow the train, the bearing allegedly failed and caused a derailment at the 23rd car.
The plastic pellets inside the railcar ignited when they were exposed to the overheated bearings, quickly spreading to the 11 other cars comprising hazardous materials, along with five full of vinyl chloride that authorities eventually decided to release and burn onsite.
The investigation established that this action was made because the temperature inside one of the tanks full of vinyl chloride was increasing.
Homendy said it was "too early to tell" for sure how the disaster could have been prevented. The official told reporters that the NTSB will continue to investigate whether industry safety standards concerning the heat threshold for high-temperature alarms and other defect detectors, rail car, wheel design and the spacing of sensors along the track require adjustment.
Norfolk Southern's inspection practices will also be investigated. The NTSB will look at whether the rail operator correctly disposed of the vinyl chloride.
Residents have blamed the fire for an increasing number of bird, livestock and fish deaths in addition to water contamination in the region, although state and federal officials claimed the air and water are safe. (Related: EPA chief downplays Ohio chemical spill, says he’ll allow his kids to drink and bathe in East Palestine's water.)
The report's release coincided with Transportation Secretary Pete Buttigieg's initial visit to the derailment site.
Buttigieg drew criticisms from Republicans for not touring the site sooner. The secretary also mispronounced East Palestine at a media conference after touring the community on Thursday.
Asked about the timing of his visit, Buttigieg asserted that he was "trying to strike the right balance" and permitting NTSB to play its role first.
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Watch the video below about the lingering health concerns after the Ohio train derailment.
This video is from the NewsClips channel on Brighteon.com.