Stamford residents woke Saturday morning to the sound of alarms blaring as the city?s emergency personnel responded to a drill at an I-95 overpass.

The practice simulated the destruction of the overpass by terrorists and the possibility of biological chemicals in the air. The Stamford Police Department says the drill was unannounced so responders would get a real feel. It was made possible by funding from the federal government.

Authorities say real emergency calls were still answered during the drill without interruption.