Imagine, if you will, a terrorist cell operating in the City of Rome.

Using downtown apartments and buying off-the-shelf ingredients, they have put together a large-scale, bomb-making operation in the heart of Central New York. They keep to themselves, are friendly to their neighbors and do everything possible to avoid suspicion.

Until one day, when the bomb-building is causing too much of a ruckus and the downstairs neighbor calls the police. A patrol officer is dispatched, heading to what he believes is just another, routine noise complaint.

What he stumbles upon, however, is something far worse.

Bomb-making materials and weapons are scattered throughout the apartment. A map of the city is hanging on the wall, the locations of all the schools marked with thumb-tacks. Posters and diagrams of airplanes and cockpit equipment are everywhere. That day’s date is circled on the calendar.

What does he do?

The National Sheriff’s Association is putting together the answer.

Sixteen first-response officers from across the northeast participated in a week-long training session for dealing with weapons of mass destruction. It was held in conjunction with the state Office of Homeland Security at the Preparedness Training Center in Whitestown, the former county airport.

The week ended with a live terrorist simulation in one of the former airplane hangers Thursday afternoon.

A group of instructors from the Sheriff’s Association staged a fake terrorist encounter, and the trainees had to react on their feet to figure out what was happening and how best to keep it from exploding.

The trainees, none from an Oneida County department, had spent four days in a classroom learning about different types of chemical, biological and nuclear WMDs; bomb detonations; radioactivity, building vulnerability and even how to handle a rowdy crowd.

They were then set loose in the hangar, where the instructors had set up several makeshift buildings to simulate terrorist hideouts. The trainees were only told that an officer had uncovered possible terrorist activity at one of the buildings, and then it was up to them to organize and deal with the ever-evolving situation. A script was in place to coordinate the different actors and role-players, but the instructors were not beyond creating spontaneous changes for the trainees. An arrested terrorist can cause a lot of trouble if he gets his hands on a police walkie-talkie.

Thursday’s session was the second first-responder training class held at the Preparedness Center this fall. Four more are planned for next year. The center has been holding classroom training since July 2006; the county airport moved to the Griffiss in January 2007.