Was it an earthquake or a sonic boom?
There are no answers yet to a significant rumble felt about 12:45 p.m. June 29 from Encinitas east to Harmony Grove and south to San Diego.
The U.S. Geological Survey reported no earthquakes around that time in the region, except for a 2.2-magnitude quake at 6:29 a.m. near Rancho Santa Margarita. Facebook users described the event as a rumble of two to five seconds, with the stronger reports coming from the North County coast. Most said they felt no ground movement, although some posters said they did.
Major news organizations in San Diego reported military officials as saying there were no operations going on at that time that would have caused such an event.
Did you feel the boom? Describe what you felt in comments below.