An accidental fireworks explosion in Simi Valley, California sent 20 people to the hospital and injured eight more, leading a bomb squad to removed the leftover fireworks.

As many as 10,000 people were in attendance at the show when some fireworks accidentally shot down, into and near the crowd, exploding by the ground:

Another witness, Annisa Wynn, told KTLA-TV Channel 5 that the explosion occurred about two minutes into the show. Fireworks suddenly began shooting sideways along the ground into the crowd instead of up in the air, she said.

“The fireworks were so close, you could see them on the ground," Wynn said. "It never happens this way. People were screaming."

The park was evacuated, and most of the injured were taken to the hospital—four with moderate to severe injuries from shrapnel or burns, and 16 others with minor injuries. Police don't think foul play was involved. No fatalities were reported.