Magnitude 4.3 Quake Hit Western Colombia Three Days Before Devastating 7.4 Mainshock

A magnitude 4.3 earthquake struck Cumbal, Nariño, on August 7, 2026, at 8 km depth with intensity 5, per Colombia's SGC. Three days later, a magnitude 7.4 mainshock killed at least 111 people and collapsed 61 buildings across western Colombia. Whether the earlier event was a geologically linked foreshock requires post-event seismological analysis, but the temporal and geographic proximity is notable.