PROPERTY, PLANT AND EQUIPMENT
 12 Months Ended
Dec. 31, 2013
PROPERTY, PLANT AND EQUIPMENT  
PROPERTY, PLANT AND EQUIPMENT

5. PROPERTY, PLANT AND EQUIPMENT

        The cost and accumulated depreciation of property, plant and equipment were as follows (dollars in millions):

 
   December 31,  
 
   2013   2012  

Land

   $ 159   $ 151  

Buildings

     730     666  

Plant and equipment

     6,617     6,270  

Construction in progress

     613     549  
           
​ ​ ​ ​ ​ ​ ​ ​

Total

     8,119     7,636  

Less accumulated depreciation

     (4,360 )   (3,980 )
           
​ ​ ​ ​ ​ ​ ​ ​

Net

   $ 3,759   $ 3,656  
           
​ ​ ​ ​ ​ ​ ​ ​
​ ​ ​ ​ ​ ​ ​ ​
           

        Depreciation expense for 2013, 2012 and 2011 was $391 million, $375 million and $374 million, respectively, of which $2 million, $5 million and nil was related to discontinued operations in 2013, 2012 and 2011, respectively.