IIRC John Cleese has a talk from years ago where he makes a very interesting point that seriousness and solemnity are two very different things.

In his opinion, killing humor is the same as killing creativity and killing creativity is the same as inviting disaster and/or failure for the sake of your ego.

Not being solemn is not the same as not being serious.

I think your last sentence there really is the right take away here. But even more than that, I think the right way to prevent future tragedies is with humor not solemnity.