Sand fell on me, unable to dig or walk out, died

I have had this happen a few times. I dig up toward the surface, and sand or gravel falls on me, suffocating me. I am unable to move, and my shovel does nothing. I end up just suffocating. Lost two stacks of diamond blocks, full diamond armor, and an inventory full of other stuff. Thanks. I love spending 8 hours searching for stuff and then dying because of a bug. Repeatedly.