NO one picked up the phone

ive seen many 9/11 videos, ive noticed that the mothers/fathers/brothers etc only have phone recordings of the phones calls they recived from there loved one in the building, they state that they werent in time to collect the phone, this happened to many people not just 5 people out of 100 but more like 80 out of 100 why?

[edit on 26-9-2006 by Revelutionnow]

More than likely due to the fact that the attacks happened during business hours. Most people were likely at work.
Just a guess on my part, but it does make sense.
Just my 2 cents.