Did it cause any damage to the tower though? How did it [COLOR=#0000FF !important]survive[/COLOR] after being hit so many times by this kind of lightning?
It did not cause any damage because of a system used in buildings since so long. Read the following short article:
Introduction:
The lightning arrester (or) the lightning conductor is a commonly used device which is used to save tall buildings and towers from the attack of lightning.
Principle:
The basic principle behind this life saving system is the "action of points" (or) "corona discharge". It is nothing but the discharge (or) leakage of electric charges from the sharp points of a charged conductor.
Construction:
The apparatus consists of a long thick rod made up of copper which is a very good conductor of electricity so that it can allow a large amount of charges to flow through it. This copper rod passes through the walls of the building. The upper end of the rod is provided with a metal plate having a number of sharp spikes which are visible at the top of the building while the lower end is connected to a plate of copper which is deeply buried in the ground so that the excess of charges is passed to the earth which is a good conductor of electricity and this process is called "earthing".
Function:
The working of a lightning arrestor can be explained either with a positively charged cloud commonly called "male cloud" or with a negatively charged cloud commonly called "female cloud". Consider a negatively charged cloud which passes over the building with a lightning arrestor. Due to the negative charge of the cloud, positive charges are induced to the sharp spikes which are at the top of the building. Now, due to the principle of action of points, leakage of the positive charges from the sharp spikes occurs so that the nearby atoms in the space are ionized into positive and negative charges. Now, the positive charges in the sharp spikes repel the newly formed positive ions and these ions try to neutralize the negative charge of the cloud. If the negative charges are not completely neutralized, these charges due to the attraction of the positive charges in the sharp spikes are passed through the copper rod to the ground where they are earthed. Thus, the intensity of lightning can be reduced thus saving the building from its destructive attack. A lightning conductor can save its surroundings for more than half a kilometer from the attack of lightning.
Usage:
Today, the lightning conductor is used almost in all tall buildings, towers and other tall spots. Hence, it is really a life saving system.
To understand more here is a simple picture about the system.