The two boys who were killed have not been identified. Alongside them, eight other spectators were injured and taken to hospital, including a 46-year-old woman who is in critical condition.
The majority of the remaining injured are believed to have not sustained life-threatening injuries, although the condition of a 26-year-old remains unknown.
Two younger children, one four years old and the other three months old, were taken to hospital for preventive assessments after the accident.
The incident took place during an event called “Airport Race Wars 2” which took place on a runway at the Kerrville-Kerr County Airport, approximately 60 miles (97 km) northwest of San Antonio. .
The event was billed as an ‘action-packed family day’ where spectators could watch ‘the fastest drag cars compete for over $ 8,000 (£ 5,800) in total prizes’.
Kerrville Police said one of the drivers “lost control and left the track, crashing into parked vehicles and hitting spectators watching the races.”
Although the length of the course (one-eighth of a mile or 0.2 km) was lined with plastic barriers filled with water, these did not extend past the finish line, meaning spectators were not protected because the cars decelerated at the end of the race.
The Associated Press quoted freelance journalist Louis Amestoy, who was present at the event, as estimating that more than 3,500 people were in attendance.
He said spectators could come within 4.6m of the track and many watched the races from lawn chairs as there were no grandstands.
Organizers had reminded participants to stay on the grass and away from the asphalt, Amestoy said, adding that the driver was nearing the end of the track when his car swerved from its path.