Fiery North Dakota derailment was latest crash to involve weak tank cars the NTSB wants replaced

The fiery North Dakota derailment that burned for days early last month was the latest train crash to involve flawed tank cars the National Transportation Safety board has been trying to get off the tracks for decades. The NTSB said in a preliminary report released Thursday that the July 5 derailment near the small town of Bondulac caused an estimated $3.6 million damage, but it didn't offer any hint about why the CPKC railroad train derailed. The NTSB highlighted the fact that some of the 17 tank cars carrying hazardous materials that derailed were DOT-111 tank cars that have demonstrated time and again that they are prone to rupturing in a train crash. Newer tank cars built with thicker steel hold up better.