Fall suddenly with motor stop

Hi guys.
I was suprised with falling my 1300mm hexacopter.
The hexa flew well so long while. So I didn’t afraid If it falls down.
I can’t recognize why my hexa stoped it’s motors.

Here is the log.
https://logs.px4.io/plot_app?log=d23ab7c5-407c-4d40-81ee-0cc3a5efddc2