The run started earlier in the week, msg's to moving money out were going on long before Thursday. Who originally triggered it, no clue... but in a bank run, those who run first make it out the door. You're not exactly taking your fiduciary responsibility seriously by thinking "oh it's probably fine! I'm sure everyone else will stay level headed and keep their money in this bank that seems to be falling over" - The FDIC in theory should to step in prior to the run, take over the bank and prevent it, they did a good job of that in many instances in 2008, not sure what happened here. It's been mentioned quite a few times in these threads, but this 60 minutes clip about 2008 is really good: https://www.youtube.com/watch?v=TAE8i40A5uI