| With hindsight, it transpires that there was little risk of lahars during the escalation phases of the eruption. |
| Unconsolidated deposits of ash may eventually mix with water to become massive, quick-moving mudflows, called lahars, that can fill in small valleys. |
| Eruption creates lahars that bury most of town of Armero and devastate Chinchiná. |
| Continued growth increases the risk of partial dome collapse, which could trigger moderate explosions and possibly significant lahars from the crater. |
| Some volcanic eruptions generate dangerous lahars that travel far beyond the volcano. |
| Major valleys cutting the volcano's flanks have been partly or completely filled in by pyroclastic flow deposits and lahars. |
