I'd like to point out that this has never, and will never, happen to Dai.

On average, Dai is very volatile compared to other stable-coins. However, this is simply because not a lot of people are using it yet. It only appears on decentralized exchanges which gives it very low liquidity.

If Dai were introduced to a platform like Coinbase where you could trade Dai directly for $1 USD, it would never lose its peg.

Anyone in the world can create/burn Dai coins using the MakerDAO platform. Dai coins are overcollateralized by a minimum of 150% worth of Ethereum. With Dai anyone in the world can take out a loan using a smart-contract and only pay 0.5% APR interest rates. Central banks cannot compete.

https://dai.makerdao.com/