ABOOBAKER ISMAIL
I will answer that.  Mr Chairperson, experience is what    made us change the approach.   At the time when we were first planning for the attacks on refineries, etc, we had no experience.  We had never been through such an operation.  We had to rely on books in this case, we also had a handbook of American Armed Forces which said that if you hit refractunating towers, you could get a vapour cloud explosion.  A vapour cloud explosion would basically be that inside of the refractunator you get the separation of the oil taking place, taking place at a high temperature, there is vapour generated as a result of it, that if that vapour escapes and if it drifts and does not explode immediately, it could drift over a civilian area and that would kill people.