The swarm of quakes are happening on the East of Ontario International Airport. As I mentioned before, the most of airports have also Reptilian Secret Underground Bases just like Denver International Airport.
The swarm is occurring mainly between Philadelphia St & Slover Avenue (South & North) and S Etiwanda Avenue & Banana Avenue (West & East). Yes, the swarm is covering only few blocks, a small area.
All of quakes are small and shallow (less than 5 km depth). This is the typical swarm caused by the cleaning up operation on Reptilian Secret Underground Base led by Galactic Federation of Light.
Industrial area = Reptilian Secret Underground Base area