Adding to the ongoing reports of mystery sounds being heard around the world, the city of Alhambra, California, has been plagued by the sounds of mysterious explosions since February of this year. To date, emergency services have received 114 reports regarding the phenomenon, where witnesses report hearing a loud explosion, strong enough to rattle windows, but no resulting flash, smoke or fire can be seen: “No one has seen the cause of the booms, smelled it or found remnants of fireworks,” according to Alhambra City Manager Mark Yokoyama, “and the calls we get don’t have enough specificity for us to find the source.”

Inquiries into the matter have yielded few results: the California Institute of Technology’s Seismological Laboratory reports no unusual seismic activity, ruling out earthquakes; queries made to the local public works and construction authority have ruled out a construction-related cause.

Alhambra’s Director of Administrative Services, Christopher Paulson, personally experienced the phenomenon, along with several colleagues. In an interview with Linda Moulton Howe, Paulson described the scene:

“The boom explosion noise I actually heard for the first time on Monday, February 22, 2016. It was following an evening City Council meeting and I and several of my colleagues were at a reception at our library right next to City Hall. It’s an open air patio on the second floor. At about 8 PM Pacific, we heard this explosion-like noise. It startled us all. We all stopped what we were doing. Conversations stopped and we looked around. We didn’t see any flames or flashes or smoke or anything else that followed except for that one loud noise. After about twenty seconds, we went back to our normal business."

Paulson went on to describe the sound as being similar to "half a stick of dynamite exploding". Calls made to the FAA and USAF are still awaiting response, and consultations with local police and fire services, and Cal Tech’s Seismology department, revealed that they were as baffled as he was.

"Police will go out to the location where the caller is and they don’t see any evidence. There’s no damage. There’s no destruction. There’s no injury. There’s no smoke. There’s no flame. There’s no kids or transients running away from the scene of anything. It’s just the loud noise."