How does one launch a class action lawsuit?

Long story short, I bought an expensive mattress from Simmons that is pretty much defunct after two years. I went online and saw that many people have had the same experience, and that the warranties aren’t honored. It also seems like Simmons was aware of the problems ahead of time. Is this the kind of thing that lawyers pick up and make into class action lawsuits? I don’t really want to spend my time on this, but I’m just curious…