The superintendent of an Orange County school district has postponed all nighttime activities this week because of concern over an earthquake swarm near the San Andreas Fault.
Scientists have been keeping close tabs on the swarm because it is rattling near a section of the San Andreas that last snapped in 1690.
The California Emergency Management Agency e-mailed local emergency responders to alert them about the swarm.
Centralia School District superintendent Diane Scheerhorn said she didn't want to take any chances.
A swarm of more than 250 earthquakes have hit close to the southern San Andreas Fault since Saturday, ranging in magnitude from 0.8 to 4.8. The swarm is centered near the thinly populated Salton Sea region in the state's southeastern desert.
