Whatever the original cause, when a shipboard fire is out of control and reaches a magazine, that can doom the ship. That was true at Trafalgar, and it's true today. But I'd bet quite a lot that there's some serious shielding around the 'box' of any of our VLS systems, just as there are around any of our magazines.

The Moskva, OTOH, had no effective shielding around its missiles, and having so many effectively-unprotected missiles in such close proximity is a recipe for disaster. If they were struck, even if there was no damage sustained below the waterline, the lives of anyone in the superstructure (including the entire bridge crew) wouldn't be worth a plugged nickel. The ship might not sink, but she'd be out of action for many months at a minimum.