[M. Dodge Thomas]

The people calling to break down the doors were idiots for sure, but this is a well understood problem in crowd control: it is common for a small minority of impatient members of such a group - from any social class - to attempt to gain entry in such situations. Unfortunately once the front ranks of such a crowd surge forward for any reason everyone behind them must move forward and keep moving or be trampled under. This is true irrespective of the intentions of individuals in the crowd, which is why you read about such incidents from time to time.

The only way to prevent this from happening is to prevent the crowd from massing in front of an exit or entry, the correct crowd control strategy is to funnel the crowd between barriers until it is reduced down to single lines of individuals. This is not a perfect strategy, but if the "funnel" is long enough it's quite effective.

Any venue which routinely experiences crowds seeking entry (for example sporting and entertainment events) has a security staff and procedures in place to deal with this even if the crowds are impatient or unruly, the problem here is either the crowd was unanticipated or that the venue was unfamiliar with crowd control.

[1rudeboy]

Bingo. Once a crowd reaches a certain size, it no longer matters what people at the front of the mass are doing, what matters is the people in the back.

And when the people in back can't see what's happening in front, stuff like this happens.