"we are in trouble if they're all incapacitated"
Yes, if it's at the same time. This is where we need social distancing ASAP, plus real support for self isolation.
And creative approaches to working from isolation. Appreciation of how difficult/impossible it is to do when you have DC (MPs who have both London and constituency houses have options unavailable to most people).
We can't stop it, but we can spread the peak. Unfortunately this shows that handwashing is not sufficient, and that community spread is occurring in central London