Nebrask

Founding of the city
Some two millennia ago, a nomadic clan of dwarves followed their herds to the site that would become Nebrask, and founded the city. Their reason for settling in one place seems lost to history, but may be associated with domesticating the herds they had previously followed. Nebrask is situated in an enormous plain with endless waves of golden grasses, which was the initial source of its moniker “the golden city”. Actual mineral gold was found, but not in such quantities to lead to massive mining operations for some centuries.

The Golden Age of Nebrask
Around a century before the fall, a little over millennium ago, a colossal vein of gold ore was found deep below the surface. The city briefly experienced a literal and figurative golden age, as their mineral prosperity increased outside trade and immigration. The golden city became gilded, and it was a literally shining beacon in the plains, and attracted attention from far and wide. More and more of the population became devoted to the mining of the seemingly endless riches from below.

The Fall
The fall was swift, and came from both above and below.

First, they attracted the attention of avarice from abroad. Before the golden age, Nebrask had not been a city worth the attention of great powers, and its wealth still mostly in the form of semi-nomadic cattle herders. The sudden appearance of massive wealth attracted attention from a loose federation of humans and evil dragons from the civilized lands of the east, and suddenly the city had enemies.

Second, they succumbed to the same downfall of miners since the dawn of time: they delved too deep. Their ore was deep, and they followed the vein deeper than deep. The specifics of who they found is unclear, but they reached the underdark, and Nebrask was unwelcome and unprepared.

Between the anvil of underdark and the hammer of raiders, the city crumbled. The structures were torn down brick by brick and the people scattered.