From "The Breifing by Tim Dickinson," Rolling Stone Magazine, May 19, 2005, pg. 42:
"According to the Deaprtment of Homeland Security, the nation's top priority should be protecting America's railways from terrorist attacks. But when the District of Columbia recently ordered trains loaded with chlorine gas and other 'ultra-hazardous' materials to steer at least two miles clear of the nation's capital, the department sided with the rail company CSX Transport, which went to federal court in April to block the D.C. measure. In its court filing, Homeland Security argues that the city's action poses a threat to 'national security, public safety, public health and a strong economy.' The former head of CSX, John Snow, now serves as treasury secretary in Bush's cabinet."
The 1984 Union Carbide disaster in Bhopal killed 3800 people when an ultra-hazardous gas leaked from one of its plants. People were found dead up to five miles from the site of the leak, according to tropmed.org.
This seems to say a lot the priorities of Bush and Co.: ultra-hazardous, but plain to see for those who will look.