New world created in 0.11.0.8.
Regression since 0.10.5

May be could be reproduce with:
Find a place with many block gravel above you and 3 blocks of any solid stone below.
Remove 2 blocks below and let one to hold the gravel. Put a torch on the wall just below the stone block. Remove the stone block. All the gravel block except one be extracted. move forward close to the torch. Minecraft PE close.
Seem the new auto-save or save worked before the crash. After re-enter in the game just move forward where gravel block was ejected previously and the game close again without any notice.

G= Gravel, S=Stone, A=AIR, T=TORCH, B=BedRock
Sample of blocks stack:

G
G
G
S(To be remove)
T
A
B

Note: This occur close to the bed rock but probably not related.

Thanks