Solve the mystery: unexplained loud boom rocks Simi Valley on St. Patrick's Day

Firetrucks respond to a loud BOOM on Sycamore drive, March 17th 2023Photo byTracy Carbone

Tonight, a little after 7pm, St. Patrick’s Day, in Simi Valley, California, a loud BOOM shook the house. At first I thought someone had crashed into the house. I ran into the other room and my family members were all looking to each other. We went outside and encountered all the neighbors walking toward the bridge on the wash/arroyo between Morley and Elizondo streets.

As we all theorized what the sound was, we noticed smoke just beyond the bridge. It quickly dissipated, as more people congregated around the bridge. The consensus was, the loud sound was caused by one really big firework.

A few minutes later, a firetruck stopped on the bridge, and several firemen explored the area. Within a short time they left.

Though there's nothing conclusive online yet about what happened, it should be noted this wasn't the first time this has happened.

A year ago, almost to the day, the same loud boom occurred. Per an article in the Acorn, “a house-rattling sound heard during the night on Sat., March 5 has left authorities flummoxed over the source.” Just like tonight, “there was a huge boom that shook many houses in the mid-Simi Valley area. Some say they called the police, but that the police don’t know what it was.”

Interestingly, last year was not the first occurrence either.

Per the Acorn, Commander Ritchie Lew stated, “We’ve had several reports of this over the years, but every time we check the area, there’s no pinpoint. We never find the source.”

At that time, fireworks weren’t ruled out. They will likely not be ruled out this year either.

San Diego heard a similar sound a few weeks ago. Per NBC 7 this event was possibly explained as the U.S. Marines were testing explosive munitions in the area. Though the sounds the citizens heard could have been attributed to the testing, this could not be confirmed. Others theorized that boom could have been an earthquake.

Who else heard the boom tonight? Comment below so we can solve this mystery.