<TABLE> <S> <C>
<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
ACCOMPANYING CONSOLIDATED FINANCIAL STATEMENTS OF WASHINGTON GROUP
INTERNATIONAL, INC. (FORMERLY MORRISON KNUDSEN CORPORATION) FOR THE NINE MONTHS
ENDED SEPTEMBER 1, 2000, AND IS QUALIFIED IN ITS ENITETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
<S> <C>
<PERIOD-TYPE> 9-MOS
<FISCAL-YEAR-END> DEC-01-2000
<PERIOD-START> DEC-04-1999
<PERIOD-END> SEP-01-2000
<CASH> 372,114
<SECURITIES> 0
<RECEIVABLES> 346,690
<ALLOWANCES> 0
<INVENTORY> 24,030
<CURRENT-ASSETS> 1,306,398
<PP&E> 446,473
<DEPRECIATION> (175,833)
<TOTAL-ASSETS> 3,239,919
<CURRENT-LIABILITIES> 1,838,227
<BONDS> 697,818
0
0
<COMMON> 544
<OTHER-SE> 414,876
<TOTAL-LIABILITY-AND-EQUITY> 3,329,919
<SALES> 0
<TOTAL-REVENUES> 2,051,344
<CGS> 0
<TOTAL-COSTS> (1,945,719)
<OTHER-EXPENSES> (56,030)
<LOSS-PROVISION> 0
<INTEREST-EXPENSE> (17,730)
<INCOME-PRETAX> 39,051
<INCOME-TAX> (15,510)
<INCOME-CONTINUING> 20,018
<DISCONTINUED> 0
<EXTRAORDINARY> 0
<CHANGES> 0
<NET-INCOME> 20,018
<EPS-BASIC> $.38
<EPS-DILUTED> $.38
</TABLE>