Survivors said there was no warning.
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Finally reaching the ash-covered summit of a still-erupting volcano in central Japan, rescue workers made a grim discovery Sunday: 31 apparently dead people, some reportedly buried in knee-deep ash.

Four victims were brought down and confirmed dead, one day after Mount Ontake’s big initial eruption, said Takehiko Furukoshi, a Nagano prefecture crisis-management official. The 27 others were listed as having heart and lung failure, the customary way for Japanese authorities to describe a body until police doctors can examine it.