WIV, the seafood market, and the airport are all on the same subway line. The topology of disease spread in cities is only approximated by physical distance.

Does it matter that they're on the same subway line? Do all people only travel on one subway line each and never change trains?

Yes it matters.

>Do all people only travel on one subway line each and never change trains?

It's not what all people do that matters when trying to find the origin of a highly contagious virus. It only takes one person going from point A to point B to cause a pandemic.

That I hadn't known. Thanks.

>WIV is fairly far from the neighborhood where things got going.

Still closer than Southeast Asia, though.

First cases to show up in the Bay Area were in late Jan 2020. That's only 6 weeks after the Chinese figured out they had a problem on their hands.