WESTVILLE, IL — (CNN) A driver careened into Labor Day parade crowd in Illinois, fracturing the skull of a 2-year-old child and injuring 10 others.

Investigators haven’t determined why the 61-year-old driver plowed into the crowd Monday morning, Officer Tom Kirby of Westville Police Department said.

“She never stopped,” one witness told CNN affiliate WICS. “It’s just too scary to see anything happen like that.”

The 2-year-old child with a fractured skull was taken to a trauma center in Champaign, Kirby said. The child’s injuries are not believed to be life-threatening.

All of the other 10 injured have been released from the hospital, the officer said. They include three other children, ages 4, 10 and 13.

Ambulances that were participating in the parade had to suddenly change course and transport the injured to the hospital, The News-Gazette newspaper reported.

“That was the good part about it — that they were there for the parade,” Westville Police Chief David Booe told the paper. Booe was also in the parade.

The driver was not seriously injured. Police are investigating why she slammed into the crowd, including whether she may have had a medical issue or a mechanical problem.

This year’s Westville Labor Day Parade was billed as one of the parade’s biggest with more than 200 entries — about 50 more than most years.

“Our parade has grown crazy this year for some reason,” organizer Darren VanDuyn told The News-Gazette.

Thousands of spectators had lined the streets of the small eastern Illinois community, about 150 miles south of Chicago, when the crash occurred.

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