It’s a safety measure.
There have been attempts to “save” Lehman over the wekend, but as of Monday morning they filed Chapter 11.
This is a good thing.
Banks and other business need to fail to signal bad business models to the market. If a bad business model is unnaturally supported by bailouts, buyouts or government take overs, it insulates the investors from the risks of bad business decisions.
Remember, we get more of that which is subsidized. So if bad business models are subsidized by bailouts, then the rot spreads and we get more investment in those bad business models until we have economy wide financial disaster instead of just a single failed business.
No good ever comes from a government bailout.