Multiple calls in case of emergency

I would like to implement a multi-party call system …

In case of emergency (eg fire) my asterisk must automatically call:
Me, my colleagues, the firemen, the police …

Where do I start ?

confbidge and originate.

However, I assume that the 112/999/911 operator will prefer not to be confused by people popping into a conference.

Also, in the UK at least, emergency centres disapprove of telephone systems that automatically dial them. (In particular, if you have a system that phones when an automated alarm goes off, you are generally required to call a commercial alarm centre, not directly to the emergency services.) If you intend to do that, you should contact them first (obviously not on an emergency number) to discuss the best way of approaching the problem.

Thank You.
I live in Italy and here is normal to automatically call 112.

I prefer to not use conference call.
I prefer to do a call to me… then a call to my secretay… then a call to another person…

After I used originate, I must to know, when this call is ended. Then I must to do a second call, then the third…

I need to have a feedback from asterisk. Because if i originate ten calls, but I have two pstn lines, only two calls will be enstablished… and I cannot know it !!
I think I must to ask asterisk if there are free outbound channels… then originate the first channel… then wait tha first call is finished (or timeout expired)… then go to the second call…(and continue)

Use the g option in Dial. You might not need originate at all.