Trains still carry lethal cargo through Dallas-Forth Worth, other American cities

one could be severe. A cloud of chlorine gas, for example, could kill up to 17,500 people and injure 100,000 others within several miles, according to a DHS report. Heavily used freight lines run through the heart of Fort Worth, Arlington, Keller, Dallas, Saginaw, and many other cities in the region.

Railroads such as Omaha, Nebraska-based Union Pacific and Fort Worth-based BNSF Railway are quick to tout their safety records. The industry, which is required by federal common-carrier law to ship chemicals such as chlorine, transported 72,000 tank cars of toxic inhalants in 2008.

That number is expected to increase dramatically in the next few years if the economy rebounds and rail freight shipments as a whole return to pre-recession levels.

Railroads, which do not actually own most of the tanker cars they transport, have supported efforts to require shippers to use the safest possible rolling stock. Recently adopted federal rules call for tanker cars to be built with a more puncture-resistant shell.

Accidents are very rare. In 2004 three people were killed by chlorine vapors in Macdona, near San Antonio. In 2005 nine people were killed and 50 injured in a train accident at Graniteville, South Carolina.

The railroads acknowledge the risk of carrying substances such as chlorine and have asked the federal government — with no luck — to limit their liability in the event that an accident or terrorist attack involving inhalants causes mass casualties.

Fort Worth, Dallas, and Kansas City, Missouri, are among the “high-threat urban areas,” or cities where the potential for a major disaster is greatest, Union Pacific argued in a petition to the Surface Transportation Board. Those cities are higher threats because they include railroad hubs within highly populated areas.

In the petition, Union Pacific asked to be relieved of its responsibility under federal common-carrier law to ship chlorine from a Utah manufacturer, U.S. Magnesium, to various points more than 1,400 miles to the east.

The long trips were “unnecessary risks” because manufacturers in Texas, Louisiana, and other states could provide the chlorine to customers, Union Pacific argued.

Dickson writes that the request was denied. Federal law requires the railroads to make such shipments as long as the supplier meets safety requirements.

In 2007 Congress required railroads to map out hazardous shipping routes around major U.S. cities, wherever possible. In many cities, such as Fort Worth, a bypass simply is not available, one Union Pacific official said.

Dallas-Fort Worth gets more chlorine gas shipments than anywhere else in the United States, one study showed. “It’s not like the interstate highway system. We don’t have a lot of routes,” said Robert Grimaila, Union Pacific vice president for safety, security and environment. “We have branch lines, but a branch line is not a main line. We don’t have a lot of options.”