One of the first things we were taught in EMT training is that if you ever need something from a crowd of bystanders you can't ask the mass, you have to pick a

One of the first things we were taught in EMT training is that if you ever need something from a crowd of bystanders you can't ask the mass, you have to pick a very specific person and address them directly. "Someone get me a crowbar" will get no response, but "You, in the red jacket, get a crowbar or something to open this" will usually get the effect you want.