It can not happen as usd has become global dependency currency and grp of different countries depend on its exchange and price change.
Well if you know the news about dollars crash from the past years. Many investors pulled out their investments on US so they did made the dollars to crash. Dollars is still vulnerable in crashing and if it happens will be affected too.
True dollar had several crash because unfavorable economic conditions, but can bounce back. If the dollar crash will affect other currencies, the price of other currencies will increase. But foreign exporters such as China and Japan does not want to dollar crash because the United States is too important customers. If the dollar crash will impact to but not too big, as there are many people who moved to use .
yeah i think it might be possible because of the economic conditions of america now a days but i think it is the fact that world or economic powers of the world doesn't wants this. i don't think this will happen but i think if it happens it will cause a great impact on the bitcoin. and from this bitcoin will lose its customers to extreme level.