My F450 Quad With PixHawk V4.0.7 Suddenly Falls Of From Sky And Not Arming Now

On 12-07-2021 I flew my quadcopter which is equipped with Pixhwak (Not Original) V4.0.7 and M8n Gps+ Compass Module. And The Frame is F450. I armed my quad normally and started to fly it, but after 5-6 min of flying the copter suddenly dropped from the sky , I was flying very low hence it dropped on my terace , my Gps Stand was Damaged due to this fall. Now after this crash the drone is not arming nor the motors are spinning. I am attaching the two log files first for the crash and second of quad not arming . Please Have A Look And Please Tell Me The Reason Of the Crash . I am a newbie to this field and I dont know how to study logs . So professional log analyzers please help me . I am really in need . Thanks in Advance for the Help.
I am attaching the log files And A Picture Of My Drone . Please Have a Look.

The 1st log shows a loss of thrust on Motor 3, then the typical drop of command on the opposite arm Motor 2 and down it goes. Motor, ESC, broken prop, etc on Motor 3.

Your vibe levels are high with clipping events. Beyond that you are flying on default parameters and haven’t done any of the pre-flight Initial Tuning. And you have no battery logging.

Initial Tuning Process Instructions (and Alt>A tuning Plug-in in Mission Planner.

Thanks A Lot For your reply . Will works on these issues mentioned by you . God Bless you !! . Thanks again