What happens if I buy at peak and can't refi in 1-2yrs from crash

[Derrick Gamez]

Wondering if anyone has had this experience or knowledge. If I purchase a property with 3.5% down and happens to be the day the market turns. The banks won't refi my property will they? Since the now current market value is lower than than what I'm in it for, basically underwater till the market turns or I pay down the note. 

Wondering how to plan for things,,, expecting to refi out in 2 years or less. But, thats always been the story when the market is good. 

Any advice or thoughts would be appreciated.