An experiment was designed to observe the evacuation drills of occupants in four mid-rise apartment buildings. Each mid-rise building contained approximately 100 apartments, with 1 to 4 persons per apartment. All printed fire safety procedures stated that upon hearing the fire alarm all occupants should leave the building or move to an area of refuge, which means the movement of 100 to 200 people for each drill. The buildings chosen for this project were characterized as mixed-occupancy buildings; that is, they included adults, children, seniors and people with handicaps. Occupants received a memo that an evacuation drill would take place during the upcoming week. The evacuations were planned and carried out with the full participation of the local fire departments. The evacuation drills were recorded on video-cameras located throughout the buildings. This paper presents the results regarding the time at which each occupant started to evacuate which varies between 30 seconds to over 24 minutes. Most occupants who heard the fire alarm started their evacuation approximately 2 1/2 minutes after the alarm activation. The impact of the alarm system, the location of alarm-bells, training and pre-evacuation actions are discussed.