Ten people died. Nine were adults and one was a teenager; the youngest was fourteen, the oldest sixty-eight. Most of them belonged to a single group of family and friends aboard the boat that took the worst of the impact — a holiday outing of exactly the kind families across Minas Gerais make every summer, ended by the few seconds it took several tonnes of rock to fall. Thirty-two more people were hurt. Twenty-seven were treated and released, twenty-three of them at the Santa Casa in Capitólio and four at the Santa Casa in São José da Barra; four were admitted to hospital. The dead were taken to Passos, where identification took days, the force of the impact having made a coroner's ordinary work slow and painful. Every one of them was Brazilian, and nearly all had come to the lake for the same reason as everyone else on the water that afternoon.

In the days afterward, Lieutenant Pedro Aihara of the Minas Gerais Fire Department explained the geology plainly to GloboNews: these canyon walls are sedimentary rock, and sedimentary rock is precisely what wind and rain take apart. The cliffs were never carved by the lake. They were drowned by it in 1963, when the Furnas Dam backed the Grande River across 1,473 square kilometres and converted river gorges into boating channels. What the reservoir left standing was more than twenty metres of exposed rock above the waterline, weathering the way it always had — only now with tourists floating at its base. On the morning of the collapse, the Civil Defense of Minas Gerais had issued a heavy-rain alert for the Capitólio region, warning of a possible cabeça d'água and telling people to avoid waterfalls during the rainy season. The alert named waterfalls. It did not occur to anyone to name the walls.

The rescue effort scaled up within the hour. The Air Operations Battalion put an aircraft over the reservoir and sent divers into the canyon; more than forty soldiers were dispatched to the region; the Furnas River Police deployed search and rescue teams onto the water. Divers had to work at the foot of a cliff that had just demonstrated what it was capable of, in a channel narrow enough that a second failure would have had nowhere to miss. Ambulances ran the injured to two small hospitals that had never been built for a mass-casualty afternoon, and both of them coped. Capitólio is a town of a few thousand people that hosts many times that number every January, and on this day the gap between those two numbers was the whole story.

The collapse was filmed from the neighbouring boats, and by evening the footage was circulating on social networks and running on broadcasts worldwide; its authenticity was quickly confirmed. President Jair Bolsonaro called the event a "regrettable disaster." For most of the world, the tragedy arrived as a few seconds of shaky phone video — a slab tipping outward, a scatter of hulls, screaming, then nothing. That clip is why the name Capitólio travelled. It is also, for ten families, the last recorded moment of someone they loved, replayed endlessly by strangers who had no idea whose afternoon they were watching.

In March 2022 the police inquiry concluded that the rockfall had been a natural event; no one was charged. That finding settled less than it sounds. In August of the same year, relatives of the victims filed a civil claim against the municipality of Capitólio seeking eighteen million reais, arguing that boat tours had been allowed to crowd into high-risk canyons without adequate regulation. The rules had already changed by then. On 13 January 2022, five days after the collapse, local decrees banned bathing in high-risk areas, capped the canyons at three boats at a time, imposed a three-knot speed limit and gave each group ten minutes inside. By 2023 the tourists were back and the operators were running again, on a lake where the risk is now measured rather than assumed away.