This article is little more than an argument about semantics. Whether prime or subprime, the real culprit was mortgage-backed securities. At the height of the bubble, banks were merely underwriting loans and they couldn't sell them fast enough as MBSs/CDOs, a market of which was experiencing its own shadow bubble. Banks were basically shifting risk off of themselves.
When housing crashed (and subsequently the MBS bubble pop), banks like WaMu and Wachovia were left holding too many loans (prime and subprime) and no market to offload them, which quickly lead to their insolvency.
When housing crashed (and subsequently the MBS bubble pop), banks like WaMu and Wachovia were left holding too many loans (prime and subprime) and no market to offload them, which quickly lead to their insolvency.