After a multitude of earthquakes inside the volcano, Colombian authorities declared a state of yellow alert on March 18.

[8] On April 14, 2008, at 11:08 pm, an ash eruption took place, prompting the government to issue a red alert and evacuate 13,000 to 15,000 people from around the mountain.

[12] On November 23, 2008, BBC News, citing Colombian authorities, announced that the eruption had claimed ten lives, with 12,000 nearby residents being evacuated and emergency services unable to reach many of the more remote affected locations.

[13] The eruption had triggered an avalanche of earth and debris that damaged houses, bridges and crops on plantations.

[15] Extensive instrumentation of the volcano, put in place by the existing national system for prevention and care of disasters,[16] which includes training of local inhabitants in high-risk regions and deployment of alarms in nearby towns, reportedly prevented large-scale deaths.