We have 90+ employees at our main branch. Our Compliance Department coordinates the drill. We usually do it in the middle of the week. Our lobby hours are 9-4. The drill usually takes place, just after 4, when the doors are locked.
We have "Security Police" who go check areas on their designated floor, either a day before, or the morning of the fire drill, they are informed of a fire drill to take place at a 4:02 PM.
At 4:02 PM, they inform the employees on their floor that there is a fire.
Then, evacuations begin to happen. Once the area's clear, the security police inspect their areas to make sure confidential information isn't left out, to make sure drawers are locked (if it was safe to do so). While this is happening, the President of the bank is speaking to the employees about the importance of fire drills. Once everything has been inspected, they get a clear signal to come back in.
In the end, we see who's aware of procedures, who leaves information out, department heads should have a list of their employees and make sure they are all accounted for.
Unfortunately, one person stays behind, the receptionist to answer phones.
Hope this kind of helps out.