Since a freight train derailed in Ohio on February 3, causing major environmental damage, there have been a number of train derailments, large and small, in different parts of the United States.。In the past two days, a freight train carrying tanks derailed at a railroad crossing in Oklahoma, fortunately causing no injuries or tank leaks, but at one point blocked road traffic;。The accident injured three conductors on board and caused diesel to leak into a nearby river。