Bomb blast in bjp rally in expert view

In 2014 there was happened a bomb blast in the rally . But how and who did that?
According to as an expert my view on this scenario is that it was preplanned by the bjp politicians.
How can i say this?
I am telling this fact because if you will try to figure out this whole scenario then there is only two points.
1. WHY THE RALLY WAS GOING ON?
(means they were knew that those bombs locations and whether that bombing will hurt them or not)

Because --
                    1.No body has dare to keep lecturing while bombs are blasting all over the entire area.
                    2.No body is having the third eye like god who can know what will happen.

2.WHY WERE THEY TAKE AUDIENCE'S LIFE IN DANGER BY KEEP LECTURING WHILE THE BOMB WERE BLASTING?

MEANS --
                    That means they don't think any value of the poor and devoted audience who were present there.
Who gave them right to risk others life.
BECAUSE --
                      If bomb were blasting then why the hell they were