The government will bail out the bank customers. It will have to, because the stakes are just too high. Letting customer (high tech companies) in sillicon valley fail would mean disaster.
In short, it seems, the bank has been unprofitable for some time and was hoping to get better. Like a junkie hopes he will dry off by making another shot.
They were obviously making less and less profit. Less profit from core business, whereas costs were soaring. Hence overall downslide.

Some bigger customers got wind that things are going less and less smoothly. These bigger customer of course got angry. And suspicious. Hence drawed all their money. And told all their big friends to do the same. And hold and behold, a true Bank run.
When FDIC, the regulator came, all was already lost. If a government official takes one day to establish there is problem, the problem is huge.
Well to be fair, the government sensed there would be a problem, since 85% of deposits were not insured. So most of the deposits exceeded 250 k USD.

Government had to act and act quickly. In a fragile financial environment, a bank run is dangerous. Imagine dominos starting to fall. It's hard to stop once they start rolling.

You see even a normally profitable and functional bank only holds about 20-30% of your money. The rest is just electronic money, fiction. So the money borrows out more money that it has. Around 3-5 times more money. So a bank run can cause a liquidity cringe. Because all that loans need to be defaulted all of a sudden, money drawn back.
And all that defaults cause of course more problems. Because people, companies don't have the money. They rush to other banks to get a new loan, so the problem starts spreading.
What is going to happen? Probably a lot of congress and senate hearings and some presidential orders probably.
In the meantime spred the risk if you have more than 250.000 USD. And/or buy US treasuries instead. Seem less risky in these times.

p.s.: You know what’s funny. Bank telling you to be carefull with your money and where you put it. And then they go and spend all of your money and have none to give you back. Because that essential a bank run is - a lot of bank hypocracy.