Oil company: Crude in Heimdal derailment had been treated to reduce volatility; Train traveling at 24 mph at time of derailment

(Source: Associated Press, May 7, 2015)

BISMARCK, N.D. — A shipment of oil involved in an explosive train derailment in North Dakota had been treated to reduce its volatility — a move that state officials suggested could have reduced the severity of the accident but won’t prevent others from occurring.

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