When the U.S. economy crashed in 2008, following the implosion of the housing market, Dave Klein’s southern California construction company almost folded. Overnight, he went from employing 40 construction workers to four. But in the past two months, Klein says, some of them have returned as he has started hiring again – moves that reflect a recent trend in the U.S. construction industry as the American economy continues to pick up steam. The U.S.