UPDATE: Did You Hear That Loud 'Boom' Thursday Night?

Readers report hearing a loud explosion occur around 10 p.m. Thursday evening in different parts of Castro Valley.

Updated April 2, 8:45 p.m.

From e-mails to Facebook posts, Castro Valley Patch received several notifications from readers about a loud "boom" that occurred around 10 p.m. Thursday evening.

From shaking windows in their homes to setting off neighborhood car alarms, some folks said the noise — which seemed like an explosion — could be felt.

One reader described the sound being "like a cannon" from her home by .

Another reader who was sitting on his patio on San Miguel Avenue describes the sound as that similiar to a dry ice bomb going off.

"When you put some dry ice in a plastic soda bottle, put some water in and close the cap, pressure builds and creates a loud boom [don't do this kids]" he posted on our Facebook page.

Sgt. JD Nelson of the Alameda County Sheriff's Office said the noise could possibly have been from someone setting off fireworks, but could not confirm this because they police were unable to trace the noise to a specific person or area.

A CVLegends Facebook reader had mentioned police activity on Marques Court near Lake Chabot. Nelson said this was due to reports by neighbors that a man was carrying what was believed to be a real gun. However, once police tracked him down, he was found with a BB gun. Nelson said the man was not arrested but added that the sounds people heard possibly could have been from gunshots fired.

This story will be updated as more information is made available.

Kathy R March 30, 2012 at 06:34 PM
I live in Hayward, Cherryland and heard the boom.....
S. Reynaga March 30, 2012 at 06:39 PM
I live in Hayward, near A Street (Burbank area) and also heard it. The dogs too!
David Ross March 30, 2012 at 10:48 PM
I heard the boom immediately followed by the sound of a helicopter. I heard the helicopter for only about 2-3 seconds then nothing. It wouldn't surprise to see if the two were related. I'm not surprise that the sheriff's department hasn't replied yet. They probably made yet another mistake and want to cover it up.
Telli March 30, 2012 at 11:19 PM
TOTALLY scared the hell out of me!! we had just gone to bed and it sounded like an explosion. It shook our entire house and then car alarms started going off. We ran outside to the sidewalk and all down our street everyone else had ran out too. We live on Lessley Ave right by Trader Joes. It was so LOUD!! Like it went off right on top of my house! I heard no helicopter or seen any flashing lights in the sky, nothing. CRAZY!!
Cal Stender March 31, 2012 at 04:56 PM
I live on Vegas Ave. It felt like something had hit the back of my house and I saw a flash come from the direction of Trader Joes. There was also the same kind of boom early in the evening last Sun or Monday from the same area.
Jim Eva March 31, 2012 at 10:24 PM
We heard it at 10:04 from our house near Redwood and Seven Hills. I thought it was another pipe bomb going off.
Michele wolf April 01, 2012 at 07:51 PM
I have heard the same boom 3 times in the last 2 months. I live close to trader joes.
Analisa Harangozo (Editor) April 03, 2012 at 03:59 AM
We spoke with Sgt. Nelson today and the story's been updated to include what he had told us.
Amber Ronzitti April 30, 2012 at 05:06 AM
We just heard it again. That was NOT a bb gun.
Heloise April 30, 2012 at 05:13 AM
Yes, scared me witless. Not a firecracker or gun - way louder!
Jay A April 30, 2012 at 05:38 AM
I caught on film one of the earliest booms 9-9-2011... the person sets them off mostly during thunder and lightening storms... Here is a boom BEFORE the lightening hits and this is comparatively very soft sounding to what is happening now and tonight. http://youtu.be/8AmJjIw6Q0s Tonight, this is about the 4th LOUD one and getting louder each time. It started months ago. The men on our block say it could be a person testing mortars that are getting stronger each time. They shoot it up in the sky. [mortar: a short, smoothbore gun for firing shells (technically called bombs) at high angles.] How is it that the news is not covering this at all? One neighbor said a house is on fire now in Hayward... don't know.
Jessica Whitney April 30, 2012 at 05:39 AM
Omg heard it again tonight about 30 mins ago!!!
Jay A April 30, 2012 at 05:43 AM
It's extremely loud and alarming. My ears are still ringing and its been about 40 minutes. There's a big flash. The house feels like a bomb went off just outside. It is very troubling.
Mike April 30, 2012 at 12:44 PM
My wife and I heard this also. Extremely loud, near the Castro Valley Blvd.-Redwood Road area. Not only was it heard, but felt as a hard vibration throughout the house. I wonder if we will now be experiencing these events, reported all over the world.
Melissa April 30, 2012 at 02:40 PM
Lots of people heard it all over Castro Valley. Any word on what it is? Facebook Discussion isn't providing any answers. https://www.facebook.com/TheCastroValley
Analisa Harangozo (Editor) April 30, 2012 at 03:10 PM
Hi All, I heard it this time as well. Really not sure what it was but I'll see if I can try and find answers.
Sarah April 30, 2012 at 03:16 PM
Heard it again last night. We live near Redwood and Lessley, but our friend who lives at Chabot and Castro Valley Blvd also heard it. It set off car alarms in both places and shook the house. Definitely NOT a BB gun. I've never seen the flash associated with the sound that some people have mentioned, but that could be because I've always been inside when I've heard it. It's always around the same time of night - 9:30 to 10pm-ish.
Sam April 30, 2012 at 05:06 PM
ANOTHER ONE!!?? This must be the 3rd one (at least) in the past 2-3 months. We heard it last night as well -- 9:45 pm-ish -- near Redwood...shook the entire house like a CANNON! What on earth is going on? I've NEVER heard anything like this before, and now we have 3 (at least) in the past couple months?! We want answers! NOW!! Why is this not getting news coverage? If this is some PG&E mess-up regarding transformers or the like, then someone MUST be held accountable, and publicly inform us. Sheriff Dept/CHP must be too busy writing cell phone tickets to investigate real safety concerns.
tami c April 30, 2012 at 10:13 PM
seriously, i am glad that i am not the only person that would like some answers. i posted a couple of links on castro valley news page, that indicate this may not be isolated to castro valley. regardless, i'm getting more and more curious since this is has become a regular occurrence and seems to happen around the same time of evening each time…… http://earthsky.org/earth/mysterious-unexplained-booms-in-alabama-georgia-michigan ….. another blog: http://forum.davidicke.com/showthread.php?t=207050
Justin Liu May 01, 2012 at 05:08 AM
I didn't hear it, although I live in the area (probably listening to music or something). From what everyone's saying, it sounds as if the boom was most likely a sonic boom from an aircraft overhead. From what I know of sonic booms, they're loud enough to rattle objects on the ground and otherwise leave no trace. This is also likely due to the numerous airports nearby. Perhaps a military test?
Megan sexton June 17, 2012 at 10:59 AM
Last night, well early Sun June 17th I heard 7 loud booms in the distance and 5 much closer to our house. We live on Rizzo in Castro Valley!!
Heloise June 18, 2012 at 03:59 AM
I heard about six or seven loud booms, with varying distance. Maybe somebody is walking up and down local creeks and setting off gunpowder, which is what it sounds like.
Trubie June 28, 2012 at 12:47 AM
I live in Sacramento, Ca and have been hearing one loud boom at night for probably the past 6 months or so. The boom comes at different times during the night... I've heard it as early as 11pm and as late as 3am in the morning. It is very strange. Sometimes the loud Boom wakes me up. I don't hear them every night but when I do they are LOUD....like a bomb went off or something. I never see any reports on the local news but today I am going to email KCRA 3 ask them if they have had any reports.
Jacquelyn Crofton July 16, 2012 at 05:01 AM
I live in the Five Canyons area in Castro Valley and I heard several loud noises Saturday night around 3 - 3:30AM that reminded me of a sonic boom. I heard another one today around 9:30PM. Does anyone know what has been causing the noise?
John Shue July 12, 2013 at 08:49 AM
I just heard a loud boom like a cannon going off at 5.39 this morning in Sacramento. Very loud


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