WorldNetDaily.com | April 19, 2004

A plot by terrorists to use dirty bombs laced with the deadly chemical osmium tetroxide to attack U.S. targets including the Sears Tower in Chicago was uncovered by British intelligence and law enforcement authorities, according to a report in Joseph Farah's G2 Bulletin. 

British police and military bomb experts passed on information to their U.S. counterparts. 

Traces of the chemical, as well as manuals for its use, were discovered by the British intelligence community during raids following the March Madrid attack. 

A number of intelligence and security agencies include osmium tetroxide in their list of dangerous materials. It can be purchased in a gel-like form in small quantities. It is mainly used for laboratory experiments. The gel is highly toxic and can be developed into a coating element for bomb parts, or into an aerosol. 

Though it is not clear from the sources that al-Qaida was behind the plot, Osama bin Laden's network had previously eyed the Sears Tower as a target, following the Sept. 11, 2001, attacks. 

The terrorist group's operations chief, Khalid Shaikh Mohammed, told interrogators that al-Qaida's follow-up attacks in the Midwest and West Coast were thwarted by the intensity of the U.S. response to the strikes on the World Trade Center in New York City and on the Pentagon. 

Mohammed said he and his nephew, Ramzi Yousuf, who was behind the first World Trade Center bombing a decade ago, had identified the targets through almanacs of American buildings. 

"We were looking for symbols of economic might," he told interrogators. 

Following 9-11, about $6.5 million was invested to improve the building's security, including more digital cameras, tightly controlled access requiring a security-approved card to get through turnstiles, additional security officers and improved communications with government and outside agencies. 

Osmium tetroxide can attack soft human tissue and can cause blindness for anyone who breathes its fumes. It can also cause an agonizing death. 

A plan to launch a chemical attack in Britain had also been prevented.