The 2013 crash happened for 2 main reasons.

1. 90% of all bitcoin trading was happening on Mt Gox. exchange. After the exchange was hacked and lost millions of dollars, they closed up shop and many people lost their money.

2. China was behind


A crash like this will almost never happen again. The infrastructure is much more robust than it was in 2013. There is tons of trading and volume on multiple exchanges around the world. There is no serious market centralization as there was back in 2013. If one exchange goes down, it won't affect the entire market. There are tons of exchanges waiting and ready to pick up. This was not the case in 2013.

China bans bitcoin, or [insert country here] bans bitcoin won't have as big as an effect as it did in 2013 because we have seen what recently happened with China. They in essence banned bitcoin again last month, and what happened? The market took a slight dip and kept on mooning. 

Bitcoin becomes more and more resilient to huge crashes. The market has matured since 2013 and become stronger and resistant to the same kinds of things which crashed it before.

I got seriously into bitcoin at the beginning of oct 2013. I also got into litecoin @ the same time. I really like litecoin because the dev is very transparent, works for coinbase, and his brother is the CEO of BTC China. I'm hoping LTC gets integrated with Mt. Gox soon, which will set off its adoption on bitstamp, coinbase, etc. I truly believe the future will contain many crypto's and BTC and litecoin will be the top 2.