CNN -- A car lost control and slammed into the pits at a racetrack in California on Saturday evening, killing two spectators, authorities said.
The crash took place during warmup laps -- an hour before the race -- at Marysville Raceway Park, about 40 miles north of Sacramento.
"It appears the driver had a stuck throttle," said Steven Blakesley, an announcer for sprint car races. He was at this race, however, as a spectator.
"He hit the left side of an opening (of the wall) near the pit area, he hit two big tractor tires which sent him airborne."
The Yuba County Sheriff's Office said one victim, a 68-year-old man, died at the scene.
The other, a 14-year-old boy, was pronounced dead at a hospital. His parent was at the racetrack with him, Sheriff's Capt. Ron Johnson said.
The driver was uninjured, Johnson said.
"I thought he was hurt -- the driver," Blakesley said. "And then (I) saw that two people were on the ground receiving CPR and people pumping on them.
"I would say it got very silent and very serious."
Sprint cars are high-powered cars that usually run on dirt or paved oval tracks.
Saturday's race was the season opener for the California Sprint Car Civil War Series.