As I understand it, these are the major Seattle company offices that are directing their HQ/office employees to work from home: Nordstrom, Microsoft, REI, Expedia, and now Facebooks stadium offices
Edit: Specified Facebook office closure limited to stadium offices based on article, it also appears Google offices in Kirkland are also encouraging WFH
F5 Tower was at least temporarily closed. Fred Hutch has gone mandatory WFH for non-essential employees.