Two reasons why this happens. 1. they over extend themselves and 2. they have about 6-8 banks doing business with them and you want to bet that each bank has a different set of financials. With all the projects these financials change daily.
Haven't heard any business leaving have you? If I was you I'd worry about the sorry state of the GF economy. The airport boardings is a good measure of how things are going with GF, the only place seeing a decline (8%) in ND.