After Sept. 11, Corzine, like so many others, started looking around to see where else we were vulnerable. One Achilles' heel sprang to mind, because about once a week, Corzine flies from D.C. into Newark International Airport. As the plane glides closer to earth, the soft-spoken former CEO of Goldman Sachs looks out the window and pictures "a plane flying into the storage tanks at all the chemical processing facilities," he tells Salon. While nuclear power plants are generally far from population centers and have fairly tight security, such is not the case with far too many chemical plants, Corzine says.

Corzine has been trying since November 2001 to get someone to listen about the risk. He wrote a bill mandating that the most dangerous of those companies conduct a review of their potential vulnerabilities and hazards and develop a plan, with the government, to make sure that these soft spots are never hit, both by beefing up security and using safer technologies. To Corzine, the bill seemed logical, sensible. The least the government and the industry could do.

Atta, after all, wasn't the first terrorist to contemplate this kind of attack. In the 1990s, law enforcement foiled two attempted terrorist attacks against chemical plants by homegrown zealots. In April 1997, four white supremacists were arrested for plotting to blow up 10 storage tanks, each holding up to 10,000 gallons of what they thought to be hydrogen-sulfide gas at the Mitchell Energy and Development Corp. near Bridgeport, Texas. (The tanks actually contained far less dangerous liquefied natural gas.)

Two years later, two alleged members of the San Joaquin County Militia were busted for plotting a millennial explosion of two 122-foot-tall tanks at the Suburban Propane storage facility in Elk Grove, Calif., near Sacramento. Elk Grove Fire Chief Mark Meaker told reporters that if such an attack were carried out, "there could be a blast of heat, shrapnel and other hazards spreading up to a mile" -- a not inconsiderable problem considering the facility's close proximity to two other industrial buildings, state Highway 99, and a housing subdivision. The San Francisco Examiner reported that the tanks contained enough propane to "immolate every living thing for five miles."

The chemical industry tends to pooh-pooh such reports, calling them alarmist. Suburban Propane said that had the Y2K militia men succeeded at exploding the tanks, the worst damage occurring to any Elk Grove area homes would be some shaken foundations and broken windows. After all, says Kate McGloon, spokeswoman for the American Chemistry Council -- to which Dow, DuPont, Union Carbide, and 190 or so others, belong -- "according to [the Occupational Safety & Health Administration] we're four and a-half times safer than any other U.S. industry."

But James Carafano, a senior fellow at the Center for Strategic and Budgetary Assessments, listens to the sounds coming from the chemical industry and hears echoes of the airline industry. "We wouldn't have had a [Transportation Security Administration, formed after the terrorist attacks] if we had been a little more stringent on our requirements on the airline industry before Sept. 11," he says. "We need to pay more attention to catastrophic attacks than we have. Someone once said, 'Don't confuse the unfamiliar with the improbable.'" Should al-Qaida strike again, it will inevitably try to up the ante, Carafano says. "And if they launch an attack on a chemical plant, they will be exposing a vulnerability we knew existed."

Kuehne Chemical Co. provides a number of products for its customers, but the ones terrorism experts are most concerned about are the chlorine it manufactures and the sulfur dioxide it sells. While the average citizen is likely to have benign thoughts associated with chlorine, its effectiveness in killing pathogens in, say, a swimming pool is what makes it so dangerous. The threat has been documented for nearly a century: At sunrise on April 22, 1915, at the second battle of Ypres, German soldiers released 168 tons of dense, greenish-yellow chlorine gas against French Algerian and territorial division troops, killing 5,000 soldiers within 10 minutes.

Sulfur dioxide, which reacts violently when mixed with chlorine, is a colorless gas with a pungent odor; if Atta had chosen to crash his plane into Tennessee's Boliden Intertrade chemical plant, he could have released 250 tons of sulfur dioxide gas into the air, potentially killing 60,000 locals, according to Boliden's own worst-case assessment.

According to Corzine, al-Qaida knows of these vulnerabilities.

And despite the lack of legislation to correct the matter, many in our government are more than aware of the risks, as well.

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