A joint, full scale training session involving local emergency responders is under way in Danbury.  The emergency response training is from 1pm to 6pm Tuesday.  People in the area of Great Plain Elementary, Broadview Middle and St Gregory the Great schools are alerted that there will be a lot of emergency response vehicles around for the exercise.  Exercise activity is confined to areas marked and closed to the public.  None of the activity is taking place along City streets, though drivers are cautioned to expect some traffic in the area of the training.