Aren't Hazmat trucks especially examined before entering major tunnels and bridges?
One of the objectives of the original WTC bombing was to blow up NYC's major tunnels.
Admittedly I haven't put all the pieces together but these people are (were?) planning another "something" very nasty and clearly wanted Hazmat credentials and trucks.
Ollie North hosted a luncheon which my family attended, but I was unable to attend, sometime this past spring. My mom came over after and was visibly upset. You see, he had created a senario of possible terrorist attack with these average "safe" looking trucks.
And so we have a war. My generation will soon learn the lesson that freedom has to be fought for, it cannot be negotiated.