The Commerce Department has lost 1,137 laptop computers since 2001, most of them assigned to the Census Bureau, officials said Thursday night. The Census Bureau, the main collector of information about Americans, lost 672 computers. Of those, 246 contained some personal data, the department said in a statement. However, no personal information from any of the missing computers has been known to have been improperly used, the department said. The number of people affected by the equipment losses could not be determined, the department said.