The government's Central Disaster Prevention Council on Dec. 19 predicted that if an earthquake of magnitude 7.3 occurred below Ota Ward, Tokyo, on a winter evening with winds blowing 8 meters per second (28.8 km per hour), an estimated 610,000 buildings would be destroyed by tremors or fire and that up to 23,000 people would be killed. Such a quake is given a 70 percent chance of occurring within 30 years.

If a quake of magnitude 8 — similar in strength to the 1923 Great Kanto Earthquake — hit, up to 70,000 people would be killed. The chance of this quake is forecast at 0 to 2 percent within 30 years.

The predicted damage is extensive. Fires in areas crowded with wooden buildings would burn for about two days; road traffic would remain seriously congested for several weeks; operation of subway trains would be suspended for about a week and ordinary trains, for about a month; and about 50 percent of Tokyo's central district would suffer from interrupted water and electricity services for more than a week. Evacuees would number 3 million the first day after a major quake, increasing to 7.2 million two weeks later.