exposing the seismic activity in Ontario could it spell danger for the region this morning a series of small earthquakes rattled Ontario California and neighboring cities the largest of these Quakes measured 3.9 on the RoR scale residents from Fontana to Riverside felt the Tremors causing widespread concern seismologist Dr Lucy Jones described the event as a small swarm along the Fontana seismicity lineation this fault line is no stranger to such activity with similar clusters occurring over the years years fortunately there were no immediate reports of significant damage or injuries the US Geological Survey is closely monitoring the situation they remind us that Southern California is an active earthquake zone preparedness is key make sure you have an emergency plan in place stay tuned for updates as we continue to keep an eye on the seismic activity in the region this is a developing story stay safe Southern California