Sand disappears when falling on a torch

*What I expected to happen was..
It should get destroyed and give the block back as an item

What actually happened was...:
It disappears with only the torch remaining

Steps to Reproduce:
1. Put a torch down
2. Make a stack of blocks next to it
3. Put a block of sand on the side off the pillar with the torch on it and it will fall on the torch and disappear