I would like to express the importance of a surveillance system in preventing urban disasters. First I present some facts about a certain tragic event, then I claim that a surveillance mechanism could have helped us prevent such a disaster and save lives.
Here goes my sentence:
An effective surveillance mechanism could have alarmed us take necessary actions and eventually save those people.
but what I really wanted to was to stress that this mechanism has the ability to sense the overcrowding. I would like to say that it could have alarmed us against overcrowding. So the kind of sentence that I intend to build is closer to following in terms of content:
An effective surveillance mechanism could have alarmed us against overcrowding, helped us take necessary actions and save those people.
But but I cannot find a way to formulate this sentence in a grammatically correct way.
I would appreaciate any help on constructing such a sentence.