This article gives a decent summary but doesn't provide any recent update. I have been wondering too and came up empty on my end.

I thought it was a unique choice of words to use "was" rather than "is" in the headline:

Dimond was a Des Moines success story.

Dimond is a Des Moines success story.

Right, I agree.

Was is the past tense. It implies that they either are no longer a success, or they are no longer in Des Moines.
I fear you might be reading too much into it though.

Doesn't imply either as the article is written, it's just a poorly written, Dateline-esque headline (that isn't a headline but two sentences in an attempt to imply narrative/conflict).

"has been" would have been my choice, but headline writers tend to go for brevity