Each day, 700,000 tanker trucks of hazardous materials line the nation's roads. And in a society that prides itself on low barriers, the licenses to operate them are only a short class - or a small bribe - away.
About 2.5 million drivers are licensed to transport toxic and explosive materials. The discovery that several people on the FBI's watch list are among them has spawned fear that, like airplanes, these trucks are essentially ready-made bombs, needing only the wrong hands at the helm to create a disaster.
"Think about it this way," says Stephen Gale, a University of Pennsylvania professor who has written extensively on terrorism, "you have all these spreadsheets looking at how to do an attack. How can you do it with the lowest costs and the greatest impact? 'Hazmats' are tailor-made."
Of the 3.8 million tons of hazardous materials making their way daily across America's roads, some can be relatively benign, like low-grade medical waste. But shipments also include things like hydrogen cyanide. "There is very nasty stuff out there, things straight out of World War I," says David Siegrist, a biological-terrorism expert at the Potomac Institute for Policy Studies in Arlington, Va.
But even run-of-the-mill materials - like gasoline for filling stations - can be used for massive explosions. To understand the damage that can be done with a common shipment of hazmats, one has to look no farther than Baltimore. In July, a train carrying hydrochloric acid, hydrofluoric acid, and the combustible lubricant tripropylene derailed in a 106-year-old tunnel. The accident halted traffic, closed roads, and caused a fire that burned for five days.
Last week, the FBI announced that it had charged 20 men with fraudulently obtaining Pennsylvania licenses to drive hazardous materials.
The bureau revealed that one driver's license examiner in Pittsburgh helped at least 18 men get hazmat permits without taking the required tests between July 1999 and February 2000. The examiner said he worked with a middleman named Abdul Mohamman, and received $50 to $100 for each person he aided. All of this followed the arrest two weeks ago of Nabil Almarabh, a man on the FBI watch list who also had a hazmat license.
The question, of course, is where do all of these threads lead. FBI Director Robert Mueller said the bureau did not believe the men with hazmat licenses were directly connected to the Sept. 11 attacks, but more attacks were a legitimate concern - albeit a hazy one.
Complicating the task is the sheer size of the investigation, which has yielded more than 200,000 leads, according to Mr. Mueller. Moreover, arrests and detentions connected with the terror probe are becoming increasingly global in scope. Investigators now believe that at least four of the 19 hijackers were trained in Afghanistan. The Sept. 11 plot appears to have roots in Germany, where terrorist Mohammed Atta went to college. Authorities last week arrested Lotfi Raissi, an Algerian living in Britain, alleging he gave some of the terrorists flight lessons. In Spain, police seized state-of-the-art equipment for falsifying documents from an Algerian group.
Mr. Gale, for one, thinks another attack may have been in the works. "All of this makes me believe they want to carry out their full plan from 1993 (the time of the first World Trade Center bombing). It was later discovered the terrorists also wanted to hit the Holland Tunnel, the Lincoln Tunnel, the George Washington Bridge, and the UN." A hazmat-trucking plan would fit with those goals, he says.
However, just focusing on hazmat licenses, Gale says, may miss a larger point. Trucking jobs are hard to fill, and schools are always needing to supply the industry with new drivers. Once people know how to drive, hijacking a shipment of hazardous materials would not be difficult, particularly considering the coordination and planning behind the recent attacks, Gale says.
The Department of Transportation last week notified transportation workers that security measures should be strengthened "as appropriate." In a "Safety Alert," the department told workers that while "it would be impossible to institute airport-style security checkpoints" everywhere, "making transportation workers aware of their surroundings" can prevent attacks.
Among the nation's truckers, concerns about hijackings have sunk in. Some CB conversations emanating from semi cabs last week discussed the possibility of carrying firearms to protect themselves - a move that would violate federal law. And an e-mail circulating listed seven things truckers should do, including using CBs to request "positive identification of all drivers hauling petroleum [all grades] or displaying hazmat placards."
Mr. Siegrist says that, even before these problems, there was increasing concern about hazmats, and it is only likely to grow now.
"There's been some progress in tightening security," he says, "but they obviously still have a long way to go."