Probably dying from lack of water. I keep mine moist. most of the time.

The pot has a drain hole?

Following because I can't seem to keep SOP alive either. I have many many succulents and they're all doing really well except for SOP and burro's tails. I can't seem to figure out the watering.

What is the soil that you have yours in? I only use Bonsai Jack.

It's not hard to get the notion that just because a plant is a succulent that it should be treated like a cactus. People are always saying, "let it dry out." Many succulent plants react very badly if the soil gets too dry.

Also, keep in mind that these low growing stringy plants tend to have very shallow roots, so, unless they're in very shallow pots, the roots are probably not reaching the bottom off the pot. Something to think about when you're letting them dry out....