An absailing rope and a point to hook it onto, might be handy for the
future or even just a rope. At least it would give them a chance of
descending relatively safely.

A rope might burn through. I think I'd prefer a parachute if the tower
were high enough.

From my parachuting days, I seem to remember that the minimum height
for a chute to open is about 500ft and that's assuming that the chute
opens perfectly, which is not always the case.

Base jumpers do it a lot lower than that.

How much lower, what is the minimum height?