Click here for a slideshow of damage from last week's earthquake,
Tuesday's quake near Chino Hills caused minor to moderate damage and few injuries.
A USC science professor says the Peralta Hills fault could generate a 6.5 magnitude quake, but the two adjoining faults could trigger a 7.5, which would be more than a thousand times stronger than Tuesday's quake.
- Get more local news headlines from the Inland Empire
- Have a news tip? Send your tips, video, or pictures