Is this the first total collapse of a "unicorn" this time around? I can't think of any recent, high profile disintegrations of this order of magnitude.
Neither Zenefits nor Uber meet that definition. Uber particularly isn't even remotely close to it. Unless you consider a company still holding a ~$50 billion valuation, with $9 billion in cash + credit line, chasing down $10 billion in sales for 2017, a total collapse.