Jensen himself set two of the dates, while Chase set the other 18. Between 1980 and 1996, four researchers took part in group activities and even stayed the night in three BUPC fallout shelters in 1980. Nuclear holocaust In 1979, approximately 6 years after being released from prison, Jensen began teaching his followers that on 29 April 1980 a nuclear holocaust would kill a third of the world's population, and that over the next twenty years, the planet would be ravaged until in the year 2000 "God's Kingdom" would be established and a thousand years of peace would follow. On the fateful night, Jensen led a group of followers into fallout shelters in Missoula, Montana. The disconfirmed prophecy resulted in Jensen losing several contingents of adherents, and his response was that he was right all along. Over the following years Jensen used several types of explanations, as noted by researcher Robert Balch, The prediction was fulfilled spiritually rather than physically. The prophecy was fulfilled physically, but not in the manner expected. The date was off because of a miscalculation. The date was a prediction, not a prophecy. The leaders had a moral responsibility to warn the public despite the date's uncertainty. God had given the world a reprieve. The prediction had been a test of members' faith. Jensen's followers had made substantial commitments to the prediction, building shelters, writing letters to government agencies and newspapers, and distributed thousands of leaflets urging fellow Missoulians to build fall-out shelters. To them the disconfirmation was "painfully obvious", and researchers used them as a case study in cognitive dissonance. On the day after Jensen's failed prophecy, the local newspaper of Missoula, Montana, the Missoulian, published the following on 30 April 1980: When asked by a UPI reporter Jensen did not express concern that the prediction might not come true, remarking "There will be a nuclear holocaust some day." Halley's Comet After the 1980 event, Jensen introduced the idea that the seven-year Tribulation had begun on the date of his prediction of a nuclear holocaust, and thus committed himself to another event happening on the same date in 1987. In 1985 he made the prediction that Halley's Comet would enter Earth's orbit on 29 April 1986, and collide with the Earth exactly one year later. In the interim year, he taught that the comet would break apart, pelt the Earth with debris, and produce massive