The 1958 rupture was the second of the re-ruptures following the enormous 1906 earthquake. Where 1942 had broken a patch of plate boundary off Manabí, the 1958 event broke the next segment to the north - the coast near Esmeraldas in Ecuador and Tumaco in Colombia. Ecuador and Colombia sit above a convergent boundary where the oceanic Nazca plate slides beneath the continental South American plate at about 55 millimetres a year. That oblique subduction stores strain unevenly, and different segments of the plate interface have different stress histories. The 1958 segment had not moved significantly since 1906. Fifty-two years of accumulated strain let go in a few seconds of shaking.

About thirty percent of Esmeraldas was destroyed. Water mains broke across the city. The power transmission lines were torn down. The highway from Esmeraldas up to Quito collapsed in multiple places, cutting the city off overland from the capital. The human toll was concentrated in specific buildings that failed. Among the worst was the Hospital, where the children's department collapsed; three children in its care died. Forty-five people across the city were injured. Beyond Esmeraldas, the shaking was strong throughout the northern provinces - Ibarra, Tulcán, Latacunga, and all the way south to Guayaquil, where it was felt but caused little damage. On the slopes of the Andes, a landslide at the village of Panado buried a reported hundred people at once. That single incident accounted for most of the total fatality count.

In Colombia, the most heavily damaged town was Tumaco, on the Pacific coast just north of the Ecuadorian border. The detail in the damage reports survives partly because the town had a tide gauge and a handful of scientific instruments - which meant observers were there to write down what they saw. The wooden pile houses common to the area rocked so violently in a north-south direction that 8-centimetre gaps opened around their foundations. A tide-gauge box at the end of the breakwater on Del Morro Island shook free; the roof collapsed and carried the instrument into the sea. A sawmill's brick ovens, used for drying pulp, crumbled. The wall of the new church cracked. Old residences and a wooden home for railway workers came down. Bottles, vases, dishes, cameras, and typewriters fell in every office in town. Water splashed out of bathtubs. On Manglares Cape, water gushed up through cracks in the ground - the classic sign of liquefaction in waterlogged coastal soil - and trees fell around the fissures. The telegraph link to La Espriella went dead for a full day as poles toppled. One Tumaco resident was badly injured. Eyewitnesses between Tumaco and Esmeraldas said the shaking was severe enough that they could not stand.

Submarine displacement along the rupture launched a tsunami. It was not the catastrophic wave of 1906, but it was enough to do harm. At Esmeraldas, a launch in the harbor nearly sank; four customs officers drowned. The waves reached Tumaco and made it as far south as Guayaquil. Smaller runups were recorded on tide gauges around the Pacific over the following day. The four customs officers are worth pausing over. Harbor workers, probably young men earning a civil-service salary that supported families back in town - the kind of deaths that do not make international headlines and do not always make the official totals. They were doing their jobs on a Sunday morning, on a launch in a harbor on the Pacific coast. The fault shifted in the sea floor nearby, and they never came home.

Many aftershocks rattled the epicentral zone in the following weeks. The two strongest came on the same morning as the main shock, at 9:45, and again on February 1. Geodetic measurements later showed the breakwater at Tumaco had risen by about 1 centimetre - a tiny, concrete measurement of an enormous, invisible event. In Esmeraldas, reconstruction began that spring. The highway to Quito was patched within a month. The hospital was rebuilt. Most of the landslide victims at Panado were never fully accounted for. In seismological terms, the 1958 earthquake became the second data point in what seismologists would later call the Ecuador-Colombia recurrence sequence: a sequence that would continue with Tumaco in 1979 and Pedernales in 2016.