Officials estimated that 4,000 people attended Saturday's “Extremo Aeroshow," in Chihuahua, Mexico, which also included performances by so-called monster trucks.
But the evening's festivities took a deadly turn when one of the trucks appeared to lose control climbing over two cars, before plunging erratically into the crowd.
El Universal put the death toll at 13, though the BBC and other media outlets said at least eight were killed. The accident also injured an additional 80 people, with eight in critical condition.
Carlos Gonzalez, a representative for the state attorney general's office, told the Los Angeles Times that the truck's driver was detained on negligent homicide charges.
“So far, the inspection indicates there was a mechanical failure, but we are investigating everything,” he said.
According to BBC News, the driver also tested positive for alcohol.
