We wonder how the virus reaches us?
This is how.
A person probably infected rides public transportation, but before being symptomatic.
A family decides not to follow the orders of the health officials. This is inexcusable, and if these facts are true, then a cordon sanitaire needs to be implemented at their home.
People party in the same place a potentially-infected person was also present.
The virus arrives in person, and then is spread. Such is sin. Such is life. Such is COVID-19.