Why would “street people” be more susceptible than anyone else? There is no science behind your claim. In fact, street people might have more active immune systems.
First, there’s the 3rd world sanitation issue (as you see in LA and San Francisco). Second, look at human waste disposal in these ‘camps’. Third, look at attention and care by the county health department (zero value in their mind). Look at the close quarters (same type conditions in WW I boot-camps that helped to spread the Spanish Flu).
Once you put a single Coronavirus ‘victim’ into a camp....he’ll infect a dozen over the next week, and the entire camp within a month. Do you really think that the county health departments will grasp this early on, and stage some kind of intervention?