A 15% critical rate is very plausible. A widely shared report [1] on Chinese media described how an entire family died to virus. A man, his sister, mother, and father all died to the coronavirus. His wife is in serious condition.

Using the reported death rates posted above, the odds of this happening are 1.3% * 1.3% * 8% * 8% = 1/924556. That's nearly 1 in a million. I concede that the medical system in Wuhan was overwhelmed, and these 5 patients did not have access to medical care.

[1] https://www.caixinglobal.com/2020-02-17/four-deaths-in-one-f...