"Artillery Shell Detonated Over Interstate 5 During Marines’ Celebration" (California)

No, the article says that the Marines say they notified the state. Did they actually? We don’t know. But there was clearly a breakdown of communications somewhere, and the simplest assumption is that the breakdown was in the organization that was shelling civilians.

It’s unlikely as an explanation of what actually happened in this specific incident. But as a hypothetical scenario of what might go wrong in a situation like this, it’s just one more reason not to conduct exercises like this one.

What the heck does “notifying the state” even mean? There are over 200 state agencies in California.

The article also says the CHP was not notified. But maybe they were. We don’t know.

Some corporal probably sent a DM to Eric Estrada’s Twitter account.

As a matter of interest, what would be the level of risk to people on the ground from a 155 mm shell exploding near the zenith of its trajectory (as opposed as an intentional airburst over a target)? I suspect in the latter case sharpnel would not merely make ‘a small dent’ in a car’s roof.

Sure, and that’s rather the point. We don’t know. Journalists should, you know, investigate and stuff and not just report the words of agency spokespeople verbatim, whether that’s the USMC or CHP or anybody else.

As a practical matter, accepting the word of the organization that did the shooting without any other corroboration is not a great thing. Especially as people who direct the activity of that organization, e.g. Pete Hegseth, are known and inveterate liars who wouldn’t be beyond ordering deliberate obfuscation.

Whatever this administration claims, it’s a safe bet that the truth is the exact opposite.

That depends on the elevation of the tube. There is such a thing as high angle fire, generally greater than 45°, for targets in defilade for example. The shrapnel that fell in the CHP car’s hood barely scratched the paint.

In the latter case, you’re correct. That is intended to inflict death or serious bodily harm.

CNN: Military report says ‘one in a million’ live fire malfunction rained shrapnel on California highway

https://www.cnn.com/2026/03/17/us/marines-celebration-investigation

From the Marine Corps investigation, this was caused by a rare malfunction in the fuze. Also, there was no evidence of operator error, and the Marines followed the approved safety procedures. This fuze type is manufactured to a tolerance of 1 defect in a million.

These were VT fuzes, variable time. They arm electronically when the projectile is fired from the tube and are set to detonate when the projectile is approx 30 feet above the ground. This is the HOB, the height of burst. The FDC (fire direction control center, that’s what I did) determines the VT setting for the appropriate HOB, and the Marines on the gun line put that setting onto the VT fuze, then they screw the fuse onto the projectile.

Articles are also saying that Marine Corps officials said the demonstration took place within an approved training area and that safety protocols including the freeway closure functioned as intended.

BUT, and this is a big but, wasn’t it Gov. Newsom who closed down the freeway when he learned this shooting was going to take place with projectiles flying across it? And, it was not the Marine Corps that initiated the freeway closure? The Marines were not planning to close the freeway when firing and when Newsom found that out he stepped in and with his authority he ordered the freeway closed for when the guns would be firing. That’s what I remember, and that’s when things got a little more political.

Other articles are also saying that the Marine Corps is reviewing the findings from the closed investigation and may adjust procedures for future demonstrations conducted near public infrastructure.

Italics mine. Gee, you think? No shit, Sherlock.

When FDC receives the call for fire, this VT fuze setting is one component in the fire command sent from FDC to the guns. The fire command sent from FDC includes:

● “Fire Mission!”, the alert warning order from FDC to the guns for, hey guys, wake up, put your toys or food away, stop shooting the shit it’s time to get to work;
● the gun number(s) that is to fire (in this case, battery, or all 6 guns [typically 6, all guns in the firing battery; or, however many guns you’ve brought with you]);
charge, the amount of gun powder to use (the gunpowder comes in bags of two different types, green powder, and white powder which is stronger than green powder; so the fire command includes, e.g., ‘charge 5 green’ or ‘charge 7 white’) — note that the gunpowder used is considered slow-burning, and it consists of little pellets shaped like little cylinders looking like cans of beer about 3mm tall and 2mm in diameter, and these little beer cans have 2 perforations in them, little holes that run through the beer can from the top to the bottom — this increases the surface area for a more complete burn of the ’powder’;
deflection, the lateral left-to-right angle to point the tube);
quadrant or quadrant elevation, the vertical angle for how high to point the tube (above 45° for what is called high-angle fire);
projectile type (in this case the projectile was the standard projectile, HE for high explosive);
fuze type (and setting, as applicable), e.g., ‘fuze VT, 26.7’ which is the time in seconds and tenths of seconds; and finally,
’at my command’ (AMC) or ‘when ready’, which is when the gun(s) are to fire the round.

For deflection, when the guns are laid (and yes that’s the term we use for the initial emplacement of the battery; all guns point in the same direction and their locations are on a controlled, surveyed point on the ground), there is the initial direction that the guns are all pointed and then you have left and right angular limits, or deflection limits, that change where the guns are pointed — the gun itself does not move but rather it’s the tube that’s mounted on the gun carriage that moves left or right.

For artillery, the two key surveyed locations are for the gun emplacements and for FO locations (forward observer).

Some other projectile types are:
ICM, for improved conventional munitions;
DP-ICM (dual purpose ICM, for both anti-personnel and anti-armor);
WP (white phosphorous which explodes and burns like hell; I’m envisioning kind of like napalm, nasty shit that once it starts burning nothing stops it until the material is expended);
illum (illumination, like a flare from a flare gun; the illum round is also WP that explodes high in the air and deploys a parachute; the WP burns bright white to provide light for visibility onto the target area);
copperhead which is a self-guided projectile that can adjust its trajectory while in flight; and
nuke for nuclear munitions.

HE projectiles are the most basic and cheap ones. The standard HE projectile for 155mm howitzers weighs 96 pounds.

Other fuze types include the following. Fuses are threaded and are screwed onto the front end of the projectile.

PD or quick, PD stands for point detonating, the cheapest and most commonly-used artillery fuze in use
time allows for the projectile to explode at a set time
delay allows for the projectile to penetrate a hard surface then explode after entry
proximity allows for the projectile to explode when near a structure like a plane; this fuze does not arm itself until it has left the tube;

Take all of this with a grain of salt. This is all from memory and more than 30 years have passed since I last thought of any of this. That said, I think all of this of pretty accurate info and I’m somewhat amazed I can still regurgitate it.

Rest assured that while 155mm artillery is nuke capable, I’ve never fired one let alone seen one.

Well, I, for one, am greatly reassured that the U.S. Army keeps those nuclear artillery shells in stock.

Wikipedia claims the W79 had a 0.1 to 1.1 kt yield, not bad, but they may have something higher-tech now.

I was under the impression that the U.S. and the Soviet Union made an agreement to retire and dismantle all of their nuke artillery shells in the 1990s.

US government spokesperson: “But we only use that for smokescreening.”

That’s exactly what I remember, and I’m relatively local.

Approved safety procedures includes not firing over friendly civilians.

Well there you go. A one in a million chance happens nine times out of ten.

You’re being facetious, right?

Of course not. “Don’t point your gun in the direction of anything you don’t want to shoot” is one of the fundamental rules of gun safety. And that applies just as much to big guns as it does to small ones. More so, even.

Well, arty rounds travel for miles and there’s bound to be friendlies between here and there. It happens all the time. It’s not uncommon.

That’s very different than small arms fire. And for that I agree with you.

For artillery there are standard safety distances, both on the ground and also in the air, that define if you’re being safe or unsafe.

But at Pendleton, firing from the beach, and close to I-5 and over I-5, was a little risky and its a good thing that Newsom shut down the freeway.