NEW YORK — While crossing a small wooden bridge March 10 near Graettinger in Palo Alto County, about 20 rail tank cars in a milelong train transporting ethanol flew off the tracks, sending fireballs into the sky, while thousands of gallons of the biofuel leaked into the creek below.

No one was injured, in part because the accident happened in a sparsely populated area. A similar derailment in the more dense Lac-Mégantic, Quebec, Canada, in 2013 killed 47 people after a train carrying crude oil crashed and exploded.

But the incident near Graettinger underscores the growing risk of another serious accident along with the increasing volume of the biofuel being moved in unit trains that are milelong with about 100 rail cars — dubbed “rolling pipelines” — to slash freight costs.

That is because ethanol shippers still are primarily using the type of rail cars that were deemed too unsafe to carry crude after the Quebec disaster, even though the biofuel is more explosive than oil.

Read the full article in the Cedar Rapids Gazette.