Two railroad tank cars containing toxic and flammable liquid toppled from a bridge into a man-made lake near Phoenix Wednesday but were not involved in a subsequent fire that broke out, local media report.
Eight to 10 cars of a 102-car freight caught fire after the train derailed on a bridge crossing Tempe Town Lake in Tempe, Arizona. However, the burning cars, several carrying lumber, remained on the bridge or near the embankment.
Two of the three tank cars that fell into the water contained cyclohexanone, used in the production of nylon. Soluble in water, the organic compound is toxic and an irritant to anyone exposed to it. It is also flammable with a flash point of 111 degrees Fahrenheit (44 degrees Celsius).
The chemical on board the third tank car has not been identified.
About 90 firefighters fought the blaze that set the bridge on fire, partially collapsing the structure, authorities said.
A derailment near the same location in late June damaged the bridge, Union Pacific reports. However, the bridge was repaired within 48 hours and passed its annual inspection in early July.