"Unfortunately, in tragedy, two of the victims were pronounced deceased at the scene. This includes an 8-year-old female and a 5-year-old male who are siblings of each other," Goodnough told a briefing.
Several other people were injured in the crash, with nine people, including three children, having been transported to hospitals with serious or life-threatening injuries, he said.
The car driver, a 66-year-old woman who crashed 25 feet into the building, was taken into custody on suspicion of driving under the influence of alcohol that caused death, the sheriff added.