All military and civilian personnel assigned to the Pentagon reservation will receive training in what to do in the event of a chemical, biological, radiological or nuclear attack, officials said Friday. The Pentagon reservation includes the five-sided building itself, the nearby Navy Annex and 90 other buildings leased by Washington Headquarters Services. More than 24,000 people will receive the training, said Army Lt. Col. Douglas Norton, officer in charge of the biological and chemical operations cell. The Pentagon, of course, was one target of the Sept. 11 terrorist attacks. A hijacked airliner slammed into the Pentagon, killing 125 people in the building and 64 aboard the airliner. But terrorists are seeking more deadly means of attack. Defense Secretary Donald Rumsfeld has said repeatedly in recent weeks that captured intelligence in Afghanistan indicates the Al Qaeda terror group was actively seeking weapons of mass destruction. Training Pentagon reservation workers how to react during an attack is the prudent thing to do, Norton said. People being assigned to the Pentagon will go through the training and there will be yearly refreshers. "This is a small two-hour block of instruction that will provide them general awareness as well as key them to some specific things they need to do to be able to respond properly if required to do so," Norton said. His group is "training the trainers" now. These people will go back to their services and offices and train their co- workers. The training is mandatory for all and will explain detection efforts inside and outside buildings, the differences between the threats and the different responses people should have to the different threats. Norton said his group is planning a series of exercises. "The work force training is the first step," he said. "We've already conducted some tabletop exercises to train the leadership, some command post exercises to train the staffs, and we will ultimately have some field training exercises." He said the first field exercise is set for May 8, when the Pentagon will participate in an Arlington County, Va., domestic preparedness exercise.