The National Trust for Historic Preservation has listed downtown Chicago's state government building to its list of the country's most-endangered historic places.
The James R. Thompson Center appeared on the Washington-based nonprofit's list this year, the Chicago Tribune reported.
Trust spokesman Virgil McDill said the Helmut Jahn-designed building is the first work of postmodern architecture placed on the list. The 17-story, curved-glass structure opened in May 1985 to house state offices.
Gov. J.B. Pritzker signed a measure in April authorizing the sale of the building, which has been hailed for its architecture but derided for its functionality.
Pritzker's office released a five-phase, 22-month timetable to ensure a sale completion within two years.
The center also has appeared on Landmarks Illinois and Preservation Chicago's endangered-building lists.