U.S. homebuilding fell more than expected in April, likely pulled down by soaring prices for lumber and other materials, but construction remains supported by an acute shortage of previously owned homes on the market. The plunge in homebuilding reported by the Commerce Department on Tuesday was concentrated in the single-family housing market segment. The number of houses authorized for construction but not yet started increased to the highest level since 1999, suggesting hesitancy on the part of builders. "Builders are delaying starting new construction because of the marked increase in costs for lumber and other ...