Reread what I wrote. In a major fire there will be significant, violent thermals pulling air into and up the building. Base jumping is dangerous even for trained base jumpers under good conditions and the fire will mean jumping in the WORST POSSIBLE conditions.So once again fuji is wrong: http://www.sosparachute.com/en/site/sos
I lost count how many times he's been wrong now, but its a lot
Your best bet is the stairwell. A rope and belay night then be useful to bypass some floors where the stairwell is inaccessible.