advice for a coworker

I just got a new job as a DNS in a large facility and I am thrilled to be leaving the place I'm at now. The ED is horrible..he's a liar and does whatever he wants regardless of anyone else. We also have a new marketing director who is rude, condescending, and quite pompous. He hasn't sold one unit since he started.
Here's the thing. I'm leaving...I'll be fine. I have a job. But there are some people staying there who are being treated horribly by either the ED or the marketing guy. I'm wondering whether to call the corporate head of HR and tell her what's going on. I think the ED is safe since we're all pretty sure they hired him to cut the budget, but the marketing guy?? If I say anything I know the HR woman will tell the ED. Frankly I'm not worried about me...if he wants me to leave sooner all the better for me since I could really use a vacation in between jobs. But I am worried that the other employees will get fired or have an even harder time. If it were just me I'd say something, but am unsure how to deal with this since other people are involved. Any suggestions? (and if anyone from my facililty is reading this... )