NEW YORK — U.S. home prices dropped at the sharpest rate in two decades during the first quarter, a closely watched index showed today, a somber indication that the housing slump continues to deepen.

Standard & Poor's/Case-Shiller said its national home price index fell 14.1 percent in the first quarter compared with a year earlier, the lowest since its inception in 1988. The quarterly index covers all nine U.S. Census divisions.

The narrower indices also set record declines. The 20-city index tumbled 14.4 percent during the quarter, the lowest since that index was started in 2001. The 10-city index plunged 15.3 percent, a record in its 20-year history.

"There are very few silver linings that one can see in the data. Most of the nation appears to remain on a downward path," said David Blitzer, chairman of S&P's index committee.

Nineteen of the 20 metro areas reported annual declines, with 15 of them posting record lows. Six metro areas lost more than 20 percent.

Las Vegas had the worst quarterly performance, falling 25.9 percent, followed by Miami and Phoenix. Only Charlotte, N.C., stayed above water, gaining less than 1 percent over the previous year