What possible ceiling do I have in my utility room?

I am in a mid-50s house with a utility room under the main roof, so it’s not an add-on. South Florida home, so it may have been built under codes for hurricanes.
The utility room entrance is on the side of the house.
Concrete floor, cinderblock walls. The ceiling looks smooth but I cannot determine what it is. What could it possibly be? I am thinking of installing large hooks in the ceiling to hang heavy parts, so I want to know if I’m going into wood, concrete block, steel, etc.
Replies
A picture might help.
Added.
It was not built to any hurricane standard if it's mid-fifties. It's probably plywood. Any hook you'd hang something on would need to go into a truss or ceiling joist, whichever you have.
Here are some images.
These two images show a hole in the ceiling and it looks like concrete is exposed but not sure.
Rock lath plaster. Can tell by the texture and that zig-zag cracking and the era is about right. I have this stuff all over my house. Thinner 2'x4' gypsum panels go up, rough plaster coat goes on, finished with smooth plaster coat.
You can put anchors into it but it won't hold real heavy stuff. Get a good stud detector, find the joists, and fasten into the joists through the plaster. Only thing is it COULD have been put on over strapping but that might be a new england thing and not something they did in florida.
Ceiling looks like it was parged with a cement based material over 2' x 4' or 8' panels. Not structural so not a good idea to hang anything from it alone. Locate the joists using a stud finder, magnet (to find nail pattern) or 1/4" masonry bit (drilling in a 1" schedule). Screw hangers or a 2x into the joists.
Frankie