In the United States, account balances up to 300K in deposits are insured. Banks are required to have FDIC on their deposits.

So this wouldnt be a bank run in the traditional sense. As we saw in 2008, deposits are safe when another bank takes over. This might be the situation here as the Fed (ironic) might have to step in, take the toxic debt off the books and sell the assets to another bank.

Being VC money, it is possible many simply had balances that exceed that level. If that is the case, it could be an expensive lesson.