They should make it a mandatory law that all companies in office buildings this high up provide every employee with emergency evacuation chutes.
And don't laugh. This is a real product on the market for only $1485. Its designed for exactly this situation where your only choice is to jump.
INFO:
The EVACUCHUTE Parachute is a last resort means of escaping a building fire or bio attack. We have all seen horrific photos of people jumping out of building windows to escape fire. Well now there is the EVACUCHUTE emergency escape parachute. The EVACUCHUTE is intended for those who live or work in high rise buildings. It is specially designed just for jumping from buildings. Unlike a conventional sport chute that sways back and forth and tends to pull the jumper back toward the building, the EVACUCHUTE has a slow steady forward descent that pushes you away from the building and not back into it. The EVACUCHUTE opens automatically with no cord to pull. Rigorously tested and TSO-C23A certified. Comes complete with parachute, carrying bag, breathing hood and helmet.