There is no way that you can safely check whether a discarded rucksack contains a bomb or not
Why would I care if it's safe? I'm also not checking it, I'm moving it somewhere it will do less damage. You can run and hide if you like, I'm going to help people if possible even if it's slightly risky to myself. If someone just dropped a bomb you have a minute to re-locate the device before it goes off, so while YOU went to go find the police BOOM fifteen people died. I just saved them.
All you can do is try to get people out of the way and call the police.
And cause a panic over something that is 99% not going to be a bomb. I hope you enjoy a good trampling!
I've said it before, in the US you're not used to terrorism
No we aren't, what we have going for us is the motivation to act for the greater good rather than saving our own skin or causing needless panic, and the willingness to take calculated risks. Basically, we can think and act in the face of potential crisis as individuals, instead of having to run to mommy. And that, incidentally, is why there are so few attacks on America compared to other places in the world. We aren't used to it because we can hand;e it better and are more likely to stop it before it happens.
react hysterically when it's too late.
You are the one claiming you would cry out to all around you to run because there might be a bomb,
Meanwhile in Boston Americans ran towards the fire to help. Where was the hysteria? The only people I saw going into hysterics were news reporters.