Is this a shell meant to go into airburst mode that just went off early, or a ground-point-impact shell that somehow detonated mid-air without impacting anything?
Most likely a shell meant to burst a few meters off the deck. Likely not a PD fuze, point detonating. So, yes, I suspect either an incorrect fuze setting or, not very likely but still possible, a faulty fuze. It may have been a VT fuze, a variable time fuze.
Thank goodness Newsome closed the freeway.
I vividly remember those signs there at Pendleton, on I-5. Some pictures quickly convey an alarming imagery.
In the 1980s and 90s you had about a 50/50 chance of having to slow or stop at a checkpoint on the I-5 about seven miles south of San Clemente in the middle of Camp Pendleton . I haven’t seen it manned in 30 years so I assumed it was decommissioned. Apparently not.
I agree, but on the other hand, 80,000 rounds per year for 20 years without a single incident (and 1 or 2 incidents per year across all of Switzerland’s 130,000 shooting club members and 2 million+ registered guns) is pretty telling.
I hesitated to even post this clip because I couldn’t (and still can’t) find any more information about some of those concerns. I assume there’s a property ownership issue that doesn’t allow them to move the targets and firing area back far enough to keep everything on the same side of the highway.
I’m surprised they didn’t run the section of highway under the line of fire either through a tunnel or at least install some type of (concrete or steel) canopy over it. It wouldn’t even have to be that strong since it wouldn’t be taking direct hits just dealing with the issues you mentioned.
I’m thinking, maybe incorrectly, that the wall is so far back from the road that a squib or anything that skips across the top of the wall and lands in traffic isn’t going to hit a car at 2000mph, it’s going to be more like getting hit with a rock that gets kicked up by the car in front of you. I mean, I still wouldn’t want to get hit with it, but it’s going to considerably slower than a normal shot for it to arc over the wall and land on the road.
But, still, setting up a range like this, at least without physically protecting the cars underneath, wouldn’t even cross my mind.
Back in my day the Marines just celebrated their birthday by getting the shit kicked out of themselves by the Tijuana cops. A good time was had by all. Why tamper with tradition?
Here is a glimpse from December 2016 of the last remaining sign in San Ysidro preserved for all time on Google Maps Street View so that we may remember the good old days when we all thought shit like this was funny. Interestingly, the LA Times wrote a story about the last remaining sign in July 2017, only for it to be stolen in September.
Especially on paydays.
Yes, that is very telling. And those Swiss shooters deserve credit.
“You wanna WHAT?”.
A very good friend of mine works for county government (different county that I work for). She works in ‘Special Projects’ or something. She was put in charge of finding land for a shooting range. Oh boy, did she ever look for expert advice. I don’t think she’s ever even touched a gun.
A fundamental difference with the Swiss shooting range is that bullets are not fused to explode at some point during flight. You can calculate with pretty good accuracy the velocities and trajectories of bullets that can both clear the protective wall and arc down to hit the road. Roads going by golf courses are probably higher risk. At least if I were the golfer.
That checkpoint was there in the late 1960’s. We were white so they waved us through.
That’s called profiling, and we all do it. I sometimes joke with my wife, who is white, that I’m surrounded by white people. 
This artillery story gets worse. According to this article ➜ Marines fired artillery over freeway without warning during rehearsal ■ , 30 rounds of 155mm artillery were test fired the day before, on Fri 17 Oct. The CHP says they were not notified but the Marine Corps says they notified the state of the test firing. So that’s a problem with the state, not the Marine Corps.
Still, firing live artillery over the Friday afternoon commute traffic may not be the smartest thing to do. Mistakes can and do happen. Like we saw that Saturday.
FYI, artillery firing over places where civilians regularly maneuver and operate is not uncommon. In several places where I’ve shot, like Camp Lejeune NC and Fort Sill OK, the trajectories track over active base roads and also places like the PX, commissary, bowling alley, and movie theater. I’m certain it happens in many other places. It is generally safe to do. But there are risks involved.
In my Marine Corps job one of my responsibilities was to construct the SDZs, surface danger zones for these indirect fire systems. The Marine Corps and the Army calls them SDZs (or SDDs, surface danger diagrams; and maybe the Navy and Air Force calls them that too, for naval gunfire and aerial bombardments). Most of the world calls it risk assessment — which I also did in my tech career developing medical devices, radiation treatment machines for cancer treatment (ISO 14971 work).
In Europe for the artillery exercises I participated in, the projectile trajectories would travel over civilian spaces that were outside of military bases, but we did not fire live ammo. Those were dry firing exercises. Boring, but much more safe.
SDZs are based on probabilities. All of artillery firing data is based on probabilities. When I was in (1980-1993) those artillery probabilities were determined and defined at the Army’s BRL, ballistics research laboratory at Aberdeen Proving Ground, MD. BRL is now closed and they do it now out of Adelphi, MD as per wiki, but I’m not sure where they do the actual shooting today because on the map Adelphi, MD is too congested an area.
But I digress.
Another way of saying that artillery firing data is based on probabilities is to say that it is based on uncertainties. And uncertainties means standard errors and likelihoods, and then on top of that you have human errors in calculations, operations and manufacturing. Add it all up and you’ll likely conclude that firing over I-5 and the commuter train tracks (the Amtrak Pacific Surfliner service; ➜ https://www.pacificSurfliner.com ■ ) at Camp Pendleton was not the smartest thing to do.
So therefore… It was the PERFECT plan for Trump to do!
So…it’s possible to have fuze timer problems. Is it also possible to have a problem with (whatever it is) propels the shell? So like, even though the fuze is ok, could it run out of gas, and fall short?
The M109A6 howitzer (which is what I assume was being used since the article describes the shell at 155mm) loads the propellant separate from the projectile. It’s certainly possible to have a misfire but while the M109 system had some teething problems in the 'Eighties during initial low rate production it’s become pretty reliable in operational use in subsequent decades, and a shell that fell materially short wouldn’t have exploded overhead but would have fallen intact and then exploded. It’s just generally kind of insane to run a live fire exercise over an active highway, much less the main thoroughfare between San Diego and Los Angeles, and especially while the Vice President was transiting. This is the kind of jingoistic and idiotic nonsense that only dictators engage in for self-gratification about what they can get away with.
Stranger
How can you tell? If the Marines didn’t notify the state, then that’s a problem with the Marines. And based on what you said, it sounds like the Marines probably didn’t notify the state.
It was an M777. The USMC doesn’t operate the M109; it only operates towed tube artillery. And is looking to replace a lot of it with rocket artillery.
The Case for Self-Propelled Howitzers | Proceedings - September 2025 Vol. 151/9/1,471
The article says the Marines notified the state.
IMO …
If that tidbit of info originated from a low-level source at Pendelton it’s probably true. If it originated in DC it’s probably false.
Yes, we have fallen that far. And are picking up speed.
Short answer: yes it’s possible. You’re talking about the propellant, also known as charge. The propellant comes in bags of 2 colors, the weaker green bag propellant and the stronger white bag propellant. You place several bags of propellant into the tube, for each round fired.
The fire command to the gun line from the FDC includes many components, and all the components are given in the same order (for clarity and consistency). One component in the fire command is Charge, e.g., Charge 4 green bag, or Charge 7 white bag.
There are at least two possible sources of error here. The FDC could miscalculate the required charge and send the wrong charge to the gun, or, the gun could receive the correct charge but place the wrong charge into the breech of the tube.
When the tube is loaded, at the breech (or, back end), the projectile is loaded first and the charge is loaded after it.
Your scenario of the round falling short due to inadequate charge is possible but (IMO) not very likely, because from the description of how the shrapnel fell, to me it seems most of the projectile and shrapnel carried downrange after the fuze detonated the round. If the round were to fall short there would be much more shrapnel and damage. But that is still possible. The details of this incident are still being fleshed out.
Yes, M777 or “M triple-7” in artillery speak. The M777 replaced the guns I shot which was the M198 (“M 1 niner 8”). Both are towed 155mm guns.