Tokyo, March 29 (BridgeNews) - The Nikkei plummeted 5% on all-round sell-off following heavy losses on Wall Street overnight. Technology issues drew heavy selling on earnings concerns following a profit warning from Nortel Networks. Weaker-than-expected Japanese industrial output data also undermined sentiment, traders said. The Nikkei headed lower throughout the day and ended at the session's low of 13,072.36, down 693.15 points.