That reminds me of the 2007 incident when the Air Force meant to transfer twelve unarmed cruise missiles from North Dakota to Louisiana but loaded up six nuclear-tipped missiles by mistake. The missiles remained unprotected on a B-52 for 36 hours before someone noticed the missiles were nuclear. A whole lot of people including 8 generals got in trouble over this.

https://en.wikipedia.org/wiki/2007_United_States_Air_Force_n...

Somewhat soberingly, earlier in the war with Ukraine, Russia managed to launch a ballistic missile with a concrete "Warhead simulator" installed, literally a mass designed to test the launch vehicle without using a nuclear device.

If that was an accident, that means they didn't properly know which warheads are where. That's.... upsetting.