Oil and natural gas can be cheaply distributed by pipeline, but ethanol must move by very expensive truck or train.

6 Feb 2011. Ohio train derailment prompts evacuations. CNN.

7 Oct 2011. Freight Train Derailment in Illinois Prompts Evacuations.   Associated Press

5 Aug 2012. Train derailment causes explosions near Plevna in SE Montana. KTVQ (Billings)

12 July 2012. Johnny Kelly. Ohio derailment explosions, fire sparked from thousands of gallons of ethanol.The Examiner.

National Transportation Safety Board investigators have begun searching for clues to the 98 train car derailment that caused spectacular explosions in Ohio’s capital. 90,000 gallons of ethanol exploded (in 3 thirty-thousand gallon tank cars).  Exploding freight cars full of ethanol made for a dramatic early morning scene in Ohio’s capital on Wednesday. The explosions were felt for blocks and sent flames shooting high in the air.

Officials say the explosions and fire following a large train derailment in Ohio early on Wednesday occurred as a result of thousands of gallons of ethanol.  The contents of the rail cars were allowed to burn much of the day on Wednesday because of the potential environmental hazard of using the foam to put the chemical fire out.

Fowler said dousing an ethanol fire requires a special foam that carries environmental risks, and crews feared that extinguishing the remaining fuel might produce a build-up of fumes and lead to another explosion.

Roughly 29.4 million carloads of freight are hauled every year across 140,000-plus miles of rail in the United States, she said. Of that, 1.8 million carloads are categorized as varying hazardous materials. Last year, about 325,000 carloads of ethanol were hauled over those lines.