I've seen this bug before.

About 27:59 my Inferno missile explodes on the south silo while launching, and there are no air units present. With Alt-B it looks like the silo starts building the next missile on that spot before the launched one is clear, so the launched one collides with the nanoframe.

It's known, and supposedly here's what happens:

1) You queue launch for missile before it's ready.
2) You have another missile queued for construction.
3) It fires right on completion while silo's buildpieces are still perfectly aligned to build the next missile.
4) Upon firing, missile stops being unit and becomes projectile.
5) Projectiles don't block build space. Silo is ok to go build next missile.
6) Since all pieces are still perfectly aligned, silo creates nanoframe for new missile during almost the same frame.
7) But projectile is still there....
8) BOOM.

Possible pathways to fix:
- disable colliding with friendlies for missile
- forced delay on building transitions in silo animation

Won't work if there's already 3 missiles and this was fourth.

An evening of descent into ever deeper, layered, levels of the silo's workings have yielded me knowledge that this has happened before - and a safeguard was put in place by allowing the missile silo workers some sleep so as no to lose their vigil.

However, one of approx. 60 launches still resulted in an accident.

So i demanded the manager to let them sleep twice more - now, for a full second. The incidents ceased shortly hereafter, and i'm now observing 11239'th launch since last accident.

I'm not sure if a second delay between building missiles is welcome when you need to get those missiles up asap, but it's better than nuking your own silo i guess...

I know, what i meant was that a proper workaround would've been cooler because it would be win on two fronts :)

But again, it's now better than it was before.

Hm alright, i'll have to agree with that.