[6][7] There were no significant earthquakes that might have warned authorities in the lead up to the phreatic eruption—caused by ground water flashing to steam in a hydrothermal explosion.

[10][16] By September 29, a total of 36 bodies had been found, and 12 people had been pronounced dead; the search was suspended due to dangerous conditions, including hydrogen sulfide gas spewing from the mountain.

[17] On September 30, fears of escalating volcanic activity on Mount Ontake continued to hinder rescue efforts.

[19][20] On October 4, 2014, four new bodies were discovered by rescuers on the slopes of Mount Ontake after searching in previously unexplored areas away from trekking roads.

[25] The victims of the Mount Ontake eruption were mourned on October 27, as authorities and residents marked a month since the volcano killed 57 people and left 6 others missing.

[26] On January 25, 2017, bereaved families of five victims filed a lawsuit against the country and Nagano prefecture, seeking damages of 150 million yen.