Domestic orders won by South Korean construction companies dropped in February for a second straight month, an industry association said Wednesday, in the latest sign of a prolonged slump in the local construction sector.Local builders bagged a combined 5.6 trillion won (US$4.9 billion) worth of new orders in February, down 39 percent from 9.1 trillion won in the same period last year, said the Construction Association of Korea (CAK)