Minecraft Items Destroyed by Gravel

So I was mining a stairway up from a mineshaft system when I was unfortunate enough to come across some falling gravel and I could not get out of it before I died. No big deal, I knew my location . I could easily get back with enough time before it all despawned. I went back to retrieve my items and only a select few were still there.. I dug around thinking maybe the rest glitched into other areas nearby. Nothing. So I guess my question is, can gravel destroy items?? The only things I got back were some random armor peices I collected, some sticks and a map. I lost everything else and it was a full inventory. There was no lava nearby or anything.. so my only guess is the gravel but I've never heard of it crushing items.. and if it does, why didnt it destroy everything? I had to mine into the gravel to retrieve what I did get back. so technically, I should've lost all of it if that were the case.