The people on the plane were not strangers thrown together by a flight schedule. They were one family. At the controls was Luiz Cláudio Salgueiro Galeazzi, 61, a São Paulo businessman who led the corporate-restructuring firm Galeazzi & Associados, and with him were nine of his relatives: his wife, his three daughters, his sister, his brother-in-law, his mother-in-law, and two nephews. They had been in the mountains together, the kind of trip families take in the warm South American December, before the holiday itself. That is the detail that lingers. This was not a commercial disaster of anonymous passengers but the loss of nearly an entire family in a single morning, leaving behind those relatives who had not boarded the plane to absorb the whole of it at once.

The flight was over almost as soon as it began. The Piper left Canela Airport at 9:12 a.m. into weather the forecasts had warned about, overcast skies and fog settling over the highlands. It traveled only about three kilometers. Witnesses and later reconstruction described the aircraft striking a chimney, then clipping the upper floor of a building, a furniture store, and a shop before coming to rest amid the businesses of Gramado. The impact sparked fires that spread through the struck buildings. The plane was modern enough, manufactured around 1989 to 1990, with documentation in order, though it was not authorized to operate as an air taxi. What brought it down so quickly is a question the weather makes easy to ask and hard to answer.

Gramado in late December is full of people. That the crash did not kill anyone on the ground, in streets and shops that busy, is its own narrow mercy, but it spared no one the experience. At least seventeen people below were injured, most from breathing the smoke that poured from the burning buildings, and two women were hurt badly enough by burns to be flown to the state capital, Porto Alegre, for treatment. The Civil Defense of Rio Grande do Sul and the state's public-security forces converged on the scene to fight the fires and reach the injured. For the shopkeepers and passersby of an ordinary tourist morning, the disaster arrived from the sky without warning, and they spent it pulling one another out of smoke.

The official response was immediate. Brazil's Aeronautical Accidents Investigation and Prevention Center, known by its initials CENIPA, opened an inquiry into how a documented aircraft with an experienced businessman at the controls came down minutes after takeoff in poor weather. The state governor went to the site to stand with the families of the victims. Galeazzi & Associados, the firm Luiz Cláudio Galeazzi had built, issued a public statement thanking those who had offered support and extending sympathy to everyone the crash had touched in the region. There was little else to say. A family that had gathered for the holidays was gone, and a town that exists to host other people's celebrations had become, for one December morning, the scene of a grief that belonged to it too.