And the FDIC is backstopped by the Fed. They have a $100B line of credit there.
In the WaMu case actually no money was lost by anyone - and they didn't even touch the Bank Insurance Fund. The Office of Thrift Supervision took control of WaMu and sold it JPMC.
Bank shenanigans have happened in the past, but at least the smaller accounts survived unscathed.
https://en.wikipedia.org/wiki/Washington_Mutual
https://en.wikipedia.org/wiki/HomeFed_Bank
(Somehow my family got caught in both of those, we weren't very good at picking banks heh)