Thank God no police were hurt, only children and teachers killed. It could have been a tragedy.
That was a decision from the leadership. Politicians. Hopefully we know more now and would go in immediately. In Mumbai, these targets were specifically chosen because they were “soft”. That certainly means that the terrorists knew there were ill trained police there, and not many at that.
Columbine was an entirely different situation. The SWAT team was acting according to policy, and if their actions amounted to cowardice, it was institutionalized cowardice.
In Mumbai, you had beat cops suddenly faced with an overwhelming military style assault. One might think that a sense of duty would require them to respond, but it would have taken great bravery, and a willingness for self-sacrifice. It would have been an outside chance to take out even one of the terrorists before going down.