Truck tumbles over side of CA freeway, lands on wreckage from earlier crash | VIDEO

SANTA CLARITA, Calif. -- As rain-soaked Southern California's roadways overnight, a series of three dangerous crashes were reported at the same spot in Santa Clarita, including a truck flipping over the side of a guardrail and crashing down on top of wreckage from an earlier collision.

The frightening pileups happened over a span of nine hours near the Highway 14 / 5 Freeway interchange.

The third and most startling of the crashes was captured on video by a passing motorist.

It shows a box truck advertising Toyo Tires apparently losing control on the upper roadway and tumbling upside down over the guardrail onto southbound truck bypass lanes below. There were already several wrecked vehicles, including a big rig, on the roadway at that spot. The box truck fell upside down and landed on top of an SUV and the already-overturned big rig.

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County firefighters tell Eyewitness News that two people were transported for medical treatment after the truck fell over the side, and another person had been transported from an earlier crash.

The CHP says the series of incidents started around 10:15 p.m. Thursday when a semitruck jacknifed, leaving the trailer hanging over the side of the road.

Another crash was reported at 6:30 a.m. Friday involving a different semi and one or more passenger vehicles. As authorities were investigating this second crash, the Toyo box truck tumbled over the side around 7:24 a.m. and landed on the existing wreckage.

The second crash also involved the spilling of about 40 gallons of fuel onto the road. Cleanup crews were called in to respond.

The CHP says it does appear weather was a factor in the crashes.