The Office of the Thrift Supervision closed down NetBank, Inc. on Friday because of its significant mortgage-related losses. The online thrift bank based in Georgia has $2.5 billion in assets but has experienced high levels of losses since 2006 caused not only by loan defaults, weak underwriting, and poor documentation, but lack of controls and failed strategies as well. About $1.5 billion of NetBank’s insured deposits will be assumed by ING Bank. According to the FDIC, those who maintained accounts over the insurance limit will become creditors of the bank’s receivership. Over 1,500 deposit accounts exceeded the $100,000 insurance limit.