The Japan Meteorological Agency on Wednesday proposed to improve tsunami warnings, after learning lessons from the March 11 disaster in which tsunami waves were underestimated in initial warnings, Japan''s News Agency ( Kyodo) reported. Under the proposal, initial warnings would say massive tsunami waves are expected to come and wreak enormous damage, without giving the estimated height of the waves, the agency said at a panel to consider disaster warnings. Reports said the initial tsunami warnings just after the magnitude 9.0 quake on March 11 underestimated the height of the tsunami to 3 to 6 meters for Iwate, Miyagi and Fukushima prefectures, leading to evacuation delays.