We have found this experience at least 3 motors in Thailand.All damaged motors were checked that FOD screen still been tight and not came apart.
These motors were sent to factory for repairing and have been sent back but the problem is happened again and again.
I noticed the compressor blade that engraved with KT marking may be broken first that make debris destroy motor.
I have reported the problem to Kingtech now and We ban K-70 at our flying club now until Kingtech will solve this problem.
I don't know why they still selling the K-70 model in KT website while they stop selling K-310 that have the same problem.