Nobody seems to fly today .
It might continue for some weeks, but after a period like that a great number of planes usually attempt to perform landing .
It's not easy to control a lot of planes, that's why ATC controller's work is considered to be extremely responsible.
Moreover, all controllers should undergo a special training courses to work at a busy airport like that.
Even if all precautionary measures were performed , It doesn't mean that something bad will not occur.
One hundred percent safety level is known to be never achieved.
That is a rule not for aviation only, but for all aspects of our life .