Moria's population of Dwarves dwindles
Event Type: Cultural/Social
Age: 3rd Age - The Kings
... the halls of Khazad-dûm were too deep and strong and filled with a people too numerous and valiant for Sauron to conquer from without. Thus its wealth remained long unravished, though its people began to dwindle.
The Return of the King, LoTR Appendix A, Annals of the Kings and Rulers: Durin's Folk
The Dwarves hid themselves in deep places, guarding their hoards; but when evil began to stir again and dragons reappeared, one by one their ancient treasures were plundered, and they became a wandering people. Moria for long remained secure, but its numbers dwindled until many of its vast mansions became dark and empty.
The Return of the King, LoTR Appendix B, The Tale of Years: The Third Age
Elena Tiriel 10Oct05