Isn't that something like partly dead and completely dead or partly pregnant and completely pregnant

My ex used to jump me when I'd make use of the phrase almost never. I think I meant hardly ever. But that seems like splitting hairs. I'm sure he knew what I meant. LOL.

wouldn't it be partially damaged?

According to American Heritage, 'partly' and 'partially' both mean "to a degree, not totally; not completely."

If something is "completely damaged" isn't it destroyed?

Isn't there a qualitative difference between damaged and destroyed? If ruffians tore up a house, tearing, breaking, slashing everything in sight and knocking holes in all the walls, it might be called completely damaged; if a meteor landed on the house and flattened it, then it would be destroyed. Possibly 'damaged' implies at least a remaining framework, whereas 'destroyed' gives the implication of nothing useful remaining of the original form.

Of course, we could also be wandering into the realm of local dialects, where we each look at Gandle's truck and use a different word or phrase in description.

I suspect you're on the right lines: completely damaged would imply that, although still standing, it will have to be demolished and rebuilt. 'partly damaged' suggests the possibility of repairs.

But I still think it's linguistic nonsense and those ideas could be expressed much more clearly.

Nobody accused the local newsfolks of being brain surgeons. rofl. We used to have a weather woman who could not pronounce precipitation. We turned the tube on at eleven p.m. just to hear her struggle.

I love it suzi. Our people drive me nuts with the "Over the night time hours" like chalk on the blackboard when "tonight" is a much neater way.

Don't get me started on our local newscasters! Al the ones around here bear a very scary resemblance to Les Nesman on "WKRP in Cincinnati."

"linguistic nonsense"

I bet I find some application for that phrase...

One that makes my teeth grind is the newscasters' gravely intoning,
"A man is dead tonight"

I always wonder if they think he might change his mind & be back tomorrow.

The one that gets me is our TV weather man that talks about the rain that "fell" today and then goes on to state that it evaporated before it hit the ground. huh??? As far as I am concerned, water up there in them thar clouds ain't rain until it hits the dirt and gets something wet.