A summit complex of lava domes and crater remnants rises above a low-angle base of volcaniclastic deposits that are dissected by radial valleys.

Three days later there was a violent eruption when a large part of the northern side of the mountain was blown away and devastating pyroclastic flows poured from the gap for a considerable time afterwards.

The pyroclastic flows and subsequent eruptions of dust and ash which filled streams and tanks, caused the death of some 3,000 people, and considerable damage.

[3][Note 1] Rescue parties which arrived on the scene were hampered by suffocating pumice dust and sulfurous fumes, and hot ashes on the ground.

As late as 5 March a major eruption occurred which threw large pieces of the volcanic dome as far as three kilometers and caused a flow of pumice and rocks for a distance of 14 km, the whole time being so hot as to set fire to every tree in its path.