During CT Scale milling operation and while POOH approximately 4490 m, suddenly the reel swivel assembly disconnected and fell on the ground along with the pumping line (~170 kg) from height of 3 meters. The supervisor immediately took all the necessary precautions, stopped pumping, and secured the well. The area was barricaded and no one from the crew was around. . SQM immediately headed to the field to evaluate the situation with PDO and decided to POOH and mobilize CT back to base for further investigation and to rectify the defective part