http://www.imperial-library.info/content/morrowind-thirty-six-lessons-vivec-sermon-thirty-three
Lie Rock, however, used the confusion to launch his own attack on the city-god, Vivec. He was hastened by all three of the black guardians, who wanted him swiftly gone, though they meant no hostility to the lord of the middle air.
The citizenry of Vivec screamed as they saw a shooting star come down out of the sky hole like a toll-road of hell. But Vivec merely raised his hand and froze Lie Rock just above the city and then he pierced the monster with Muatra.
(The practice of piercing the Second Aperture is now forbidden.)
When Nerevar returned, he saw the frozen comet above his lord's city. He asked whether or not Vivec wanted it removed.
'I would have done so myself if I wanted, silly Hortator. I shall keep it there with its last intention intact, so that if the love of the people of this city for me ever disappear, so shall the power that holds back their destruction.'
Nerevar said, 'Love is under your will only.'
Vivec smiled and told the Hortator that he had become a Minister of Truth.
The ending of the words is ALMSIVI.
That's the deal with the Ministry of Truth.
As for what happened, the Ministry of Truth fell after the ingenium blew up (a machine used to keep Vivec's enchantments intact, and powered by souls). After the MoT fell, Red Mountain blew up (it is a volcano), and after the devastation, the argonians, lead by the Hist, took the opportunity to strike at a foe that has been hounding them since the first era.