Both the minivan and the big-rig were traveling westbound on I-580 at about 10:30 a.m. Friday. Witnesses told the CHP the van appeared to be traveling at the speed limit in the fast lane on a very wet highway.
"It began to fishtail, veered to the right, struck the truck which was about 55 mph in the right most lane and then veered back to its left, overturning," CHP spokesperson Steve Creel said.
The van ended up on its wheels after rolling over. Creel says that is when the 7-year-old girl was thrown from the van.
"The initial observation was the side door opened on the van and the...female passenger laying on the pavement of the freeway," he said. "Right now, the question we're looking at is whether all the occupants in the van had their seat belts on."
The trailer which the minivan struck fishtailed and overturned on the shoulder, spilling its load of grapes onto the freeway. The driver of the truck was not hurt.
Creel says the minivan's two back tires were extremely worn -- a possible factor in the accident.
"In fact, the back two tires on that van had the belted chord, steel belts showing through it and were unsafe to drive on," he said.
The CHP canceled the sig-alert at 2 p.m.