Oh, something I have MUCH too much experience with! We had an enormous glass table picked up by a microburst last summer, it smashed into a gazillion pieces and was thrown all over our deck and into the pool. (photos below) In the photos it looks like mostly large pieces but in the pool there was almost a fine dusting of glass pieces, along with larger chunks. We could sweep glass into a little pile with our feet underwater, it was everywhere!

What I did was run the automatic cleaner 24 hours a day for a few days (we picked up all the big pieces first), emptying the bag frequently, then I put on a mask and snorkel (and swim shoes!)and I meticulously vacuumed inch by inch, once a day for at least a week! I don't believe YOU will need to be that thorough since it wasn't an entire table chunked into your pool, but the mask/goggles with the vacuum might work well for your situation. It would appear clean until I got in there with a mask and I could see more glass.

Here is a link that might be useful: storm damage