Where is the 'explosion like noise' coming from? [Updated]

UPDATE 3.11.2016

We have updated the map based on new reports from our readers.    

A couple readers commented on our website and Facebook page saying they first heard the “explosion like noise” in January. Most reports said that the noise was heard during nighttime. Some people claimed they have heard it multiple times a day. 

“I've heard repeated short blast sounds on Sunday mornings when local and traffic noise is very low,” W Nickman commented our website.

Some residents living in the south side of Alhambra said they have heard the noise and think the source is on the north side. Residents from San Marino, South Pasadena and El Monte said they have heard similar noises, but they can’t determine the source. 

“El Monte residents also complain about the same issue,” Teresa Arroyo commented on our Facebook page.

Some readers think the noise might be from fireworks. “I first heard it back in January, so i thought it was leftover fireworks being lit,” John W commented on our website. But others said the noise is louder than a regular firework explosion. A few residents said they have not heard the noises since the recent power outrage, which happened two weeks ago.

Jayson Chan, a resident living on Stoneman Ave, told the Source in a Facebook message that he thinks the noise might be from the malfunctioning heater furnace in his building. “I believe it may be the heater furnace. There is a delay in ignition so the gas builds up and creates a loud explosion,” wrote Chan. He doesn’t have the evidence to prove it, though he has reported it to the APD and his homeowner’s association. He says the furnace will soon be inspected by professionals.

3.3.2016

“I know this sounds weird. But since living in Alhambra every other night or so I hear a loud explosion like noise, ” Noelle Dominguez wrote Feb 16 on Nextdoor.com, a community social media site. Other residents replied to her post and reported hearing the same kind of noise.

A couple readers have also commented on the Source’s Facebook page saying they have heard similar noises at different locations in Alhambra recently, but neither of them had a good guess about the cause of the sounds. The Alhambra Police Department posted on their Facebook page saying they have also received reports about an unidentified “explosion like noise." The Alhambra Fire Department does not have information about the noise, and Southern California Edison told the APD they have not had any reports of outages or blown transformers.

According to the Alhambra Public Works Department, there are ongoing construction projects on Valley Boulevard, but the department does not believe that the projects are the source of the noises. No construction-related explosions have been conducted recently, according to the department. The Aviation Division of the County of Los Angeles Department of Public Works said they do not have an explanation for the noise either.

The Source has created a map based on the reports from our readers. The red markings indicate the approximate locations where readers have heard the noises. If you have heard a similar noise or believe you know the cause of it, please comment below and report to the APD at (626) 570-5151.

15 thoughts on “Where is the 'explosion like noise' coming from? [Updated]”

  1. I live in Rowland Heights and my parents and I just heard two explosion-like sounds

  2. There was huge explosion-like sounds just now.
    I am wondering if this sounds is gunshot noise or not.
    Feeling not so confortable!!

    1. yeah I heard that in my house on 2nd St

  3. Last night we had similar explosion like sound that set nunch of car alarms past 2 am in long beach of alamitos and 1st street

  4. This isn’t anything new. It’s been going on for at least the 18 years I have lived in S. Pas, but I don’t know what it is. It’s not the skeet range, because it happens at night. It might be power line transformers arcing or sounds from a power substation; the power grid is very troublesome this neighborhood.

  5. Orange Hill in Long beach, at least 4-5 times a week after dark.

  6. In roseville ca. two recent accounts of these explosion noises around 8 pm. There are trains for cargo that pass by multiple times a day, but i wouldnt recognize any related excusable sounds at a busy train station.

  7. I was lying on my bed and heard a loud noise which made me startled. I don’t know what it is, or the cause of it. At first, we thought there was an accident at the freeway, since we live near the freeway. We checked outside our house and saw the red thingy (like a plant pot) upside down, our neighbor said that was the drain (the red pot), it has nothing to do with the noise. So I guess it was loud enough to make the pot upside down? I don’t really know and I’m scared. My neighbor told us that they already reported it to the Alhambra police department and they also heard it. I want to know what it is and what the cause of it. It’s driving me insane.

  8. Muffled, distant, gunshot like sounds have reached my former home in SG Village, and for decades in W Alhambra. They are most clear on Sunday mornings, when local and traffic noise are nil. I believe the sounds come from the Rosemead/El Monte Skeet and shot range when the atmospheric conditions allow this sound to travel.

  9. Hmm…Possibly another “Porter Ranch” situation in the making???

  10. Eric Hendrickson

    We have heard 4-5 explosions over the last month or so. Some louder than others. We are at 800 block n marguerita ave

  11. IIRC, i first heard it back in January, so i thought it was leftover fireworks being lit. But look at the spatial distribution on the map, im going to guess that the culprit is setting off large fireworks in the flood channels. That would explain why it sounds like the sound is travelling north and south.

  12. Has Almansor Park (or another facility) employed the use of a gas/propane cannon to scare off wildlife/birds?

  13. Possible the explosion like sounds are coming from the the work on the railroad trench being constructed in San Gabriel near the Alhambra border on Mission Rd

    1. Also similar explosion sounds on may 9 2016 , evening, in roseville from the direction of the train station nearby.

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