Mexico monster truck driver detained amid suspicions he was drunk during horrific crash that killed 8 spectators and injured 79 Twelve spectators remained in intensive care Sunday with four in critical condition after the truck shot into the audience at a Chihuahua, Mexico air show Saturday Witnesses say they saw the driver hit his head on the inside of his truck just after a car-jumping stunt and before deadly crash By Ashley Collman and Ap Reporter The driver of an out-of-control monster truck that shot into a helpless crowd of spectators at a Mexican air show Saturday killing eight people and injuring 79 may have been drunk. Authorities say alcohol was detected on the breath of Francico Velazquez, who was performing stunts a the event on the outskirts of Chihuahua. Velazquez was detained Sunday on suspicion of manslaughter and investigators are also looking into possible safety violations in the setup of the show. Out of bounds: At the Extreme Aeroshow in Chihuahua, Mexico Saturday, a monster truck driver lost control of his vehicle and drove into a crowd of spectators Lost control: Witnesses say they saw the driver bang his head and lose his helmet before driving into the crowd Carlos Gonzalez, spokesman for the Chihuahua state prosecutors' office, said Velazquez appeared to lose control of the truck after leaping over cars it was crushing during a demonstration at the Extreme Aeroshow. Video taken from the stands by spectator Krizthall Martinez shows the truck making an initial pass over two cars. It then makes a second pass at higher speed, coming down sharply nose first and bouncing violently before piling straight into the crowd, which stood directly in the path of the monster truck unprotected by any wall or barrier. Spectator Daniel Dominguez, 18, said he was happily watching the show with a group of relatives when the truck came down hard in the middle of the cars. Chaos: Injured people are treated during the panic that ensued following Saturday's horrific tragedy Aftermath: Horrified family and friends of victims search the crowd for their loved ones. On Sunday, 12 people remained in intensive care with four in critical condition "The driver hit his head and his helmet flew off," Dominguez said. The truck came directly at where we were. The governor of the Mexican state declared three days of mourning to honor victims. The three-day show, which included performances by airplanes, the monster truck acts and other events, was canceled after the accident on its second day in a park on the outskirts of Chihuahua, the capital of Chihuahua state. On Sunday, two armed men threw a firebomb at monster trucks and other vehicles parked at a hotel that were part of an unrelated monster truck production at the air show. Chihuahua Gov. Cesar Duarte Juarez said his administration, which was listed as a sponsor of the air show, was investigating whether Civil Protection authorities had correctly enforced safety regulations. He and other officials didn't say if those regulations required any protective barrier for spectators. Some witnesses said the driver appeared to have hit his head on the interior of the truck, which is nicknamed "Big Show," as he drove over the old cars. At least two reporting seeing the driver's helmet come off before the huge vehicle drove into the crowd of terrified spectators, who tried to flee. It hit me and threw me to the other side," Jesus Manuel Ibarra, 41, said as he was treated for injuries to his arm and hip. Chihuahua Mayor Marco Quezada said 79 people had been hurt. Twelve remained in intensive care, with four in critical condition, he said. Gonzalez, the prosecutors spokesman, said investigators were looking into the possibility of a mechanical failure that left Velazquez unable to release the gas pedal. Several witnesses said, however, that the driver appeared to have become incapacitated after striking his head as he bounced over small cars at high speed, crushing their roofs. In custody: The monster truck driver survived the crash and was arrested Sunday on suspicions of manslaughter. Tests indicated he may have been drinking