Item Duplication Glitch

On a Minecraft realms Server, I died at a Skeleton Spawner. I spawned back at spawn point and went to collect my items at the death point. However, I when I got items again, more items (Exactly as my inventory) appeared on floor as if I had died, and my minecraft was lagging. I think the server crashed too because I got kicked. When I logged back in, I had died. So I then I went back to the place I died and saw 2 copies of each item, with equivalent damage etc on the floor. I was lagging too, however, this has never happened before.

Note: I died in the Skeleton Spawner Room.

I also got kicked when I collected my items (when the server crashed).