The active voice of the verb is like this:
Ich kümmere mich um die Kinder.
But I know the passive voice of that verb is like this:
Es wird sich um die Kinder gekümmert.
Now my question is: Is sich in the second sentence (the one in the passive voice) redundant? I can't get rid of this feeling that tells me you can get rid of "sich" and the sentence would be like this:
Es wird um die Kinder gekümmert.
Is the third sentence right? Do the Germans remove it in colloquial language?