I read an article on Fortune.com on the 10 largest US Bankruptcies. Here are their Names as per the Rank, Date of Bankcruptcy and Assets lost. I have also added the type of organisation it was, for reference.
Lehman Brothers Holdings
Rank: 1
Type: Investment Bank
Date of bankruptcy filing: 09/15/08
Assets: $691 billion
Washington Mutual
Rank: 2
Type: Bank
Date of bankruptcy filing: 09/26/08
Assets: $327.9 billion
WorldCom
Rank: 3
Type: Telecom
Date of bankruptcy filing: 07/21/02
Assets: $103.9 billion
General Motors
Rank: 4
Type: Automobile
Date of bankruptcy filing: 6/1/09
Assets: $91 billion
Enron
Rank: 5
Type: Energy, Electricity and Natural Gas
Date of bankruptcy filing: 12/02/01
Assets: $65.5 billion
Conseco
Rank: 6
Type: Insurance & Finance
Date of bankruptcy filing: 12/17/02
Assets: $61 billion
Chrysler
Rank: 7
Type: Automobile
Date of bankruptcy filing: 04/30/09
Assets: $39 billion
Thornburg Mortgage
Rank: 8
Type: Real Estate Investment Trust
Date of bankruptcy filing: 05/01/09
Assets: $36.5 billion
Pacific Gas and Electric Co.
Rank: 9
Type: Electricity and Gas
Date of bankruptcy filing: 04/06/01
Assets: $36 billion
Texaco
Rank: 10
Type: Oil & Petroleum
Date of bankruptcy filing: 04/12/87
Assets: $34.9 billion
Full article:- http://money.cnn.com/galleries/2009/fortune/0905/gallery.largest_bankruptcies.fortune/index.html