On the evening of March 11, 2008, news reporter and cameraman, Angela Vidal and Scott Percival, are assigned to follow firefighters Jake and Fletcher during their nightshift. They are given a department tour, but an emergency call dispatches them. Arriving, screams from a self-barricaded apartment block room were heard by the landlord and residents. The firemen, police officers, and crew enter; they are attacked by an aggressive elderly woman. Fletcher also mysteriously falls to the base floor, incapacitated. The old woman bites a policeman and is killed. As the residents are ordered downstairs for their own safety, the team finds a second woman in a similar condition and bring her downstairs with others.