Witnesses described a terrifying chain of impacts, with vehicles crushed against the retaining bank and others spinning out of control on the slick pavement. The trailer, jackknifed across the Mexico-Querétaro Highway, became both the cause and the barrier, sealing off the route and trapping dozens of motorists in a nightmare of mangled metal and blaring alarms. Emergency crews fought the rain and chaos to reach the injured, stabilizing victims on the asphalt as traffic stretched for kilometers behind the scene. While authorities now reconstruct the moments before the crash, they are already pointing to excessive speed, limited visibility and wet conditions as a lethal combination. For the families who waited for calls that night, the investigation offers little comfort; in a few violent seconds, an ordinary commute became a permanent dividing line between before and after.