This civilization, according to Churchward and many others, was very technologically advanced but was destroyed due to natural disaster. After viewing rubbings of Niven's tablets Churchward strongly believed that there were a group of people that escaped destruction and migrated to other parts of the world spreading their culture and belief system.
Churchward, based on his study of Niven's tablets and the civilization's advanced technology, believed that this civilization was destroyed by natural disaster but that some survivors escaped and spread their culture and beliefs elsewhere.