As a subordinate, how have you dealt with toxic leadership?

Our current 1SG, who is a SFC, started out as a great leader and role model when he first took responsibility, but over the course of the last few months he has become the most toxic leader I have met thus far in my career. I understand that he is serving in a position that comes with a great deal of stress and that alone can take a toll on anyone, but it is just getting out of hand. It's to the point now that if you so much as try to bring up a method or opinion that isn't exactly in line with his, you get punished. For instance, one of the best squad leaders we have in the company simply disagreed with the method in which a training event was being handled, and brought it up in a totally respectful manner, and now he is no longer a squad leader. On top of that, the 1SG completely disrespected him in front of the entire company, junior enlisted, NCOs, basically everyone, and was screaming in his face and calling names even. This isn't the first instance of something like this happening with him, and probably won't be the last. It has dragged morale down to an all time low in the company, and made it nearly impossible for leaders to do what they do best, mentor and train Soldiers in innovative ways using the knowledge that they've gained from their experiences. We're just not sure how to handle the situation without sounding like we're just complaining. It's a serious issue, and needs to addressed, but no one wants to put their career on the line. Any suggestions would be greatly appreciated, and I'm not trying to put the man down but things have to change for the good of the unit and the Soldiers in it.