A person has died as a result of injuries sustained in a collision on the northbound 14 Freeway in the Agua Dulce area.

The trouble began Saturday at about 11:25 a.m. when a big-rig struck a woman who was outside of her vehicle, on the side of the freeway just north of Agua Dulce Canyon Road. One or more witnesses reported to the California Highway Patrol that the woman was working on her vehicle when the semi-truck hit her.

The woman was lying in the roadway and the big-rig took off. It is not yet clear whether the driver knew he struck the victim; CHP officers went off after the truck.

The three right lanes of the freeway were closed (leaving one open), and  a Sigalert was issued.

Then, a bit more than an hour later, around 12:45 p.m., an SUV was approaching the stopped traffic when it rear-ended another vehicle and rolled over. The result was a new 4-car collision south of Agua Dulce Canyon Road.

It was not immediately known which collision resulted in the fatality – the first one where the woman was struck, or the subsequent multi-car pileup.

A Sigalert was issued for all lanes, and traffic was backed up for at least five or six miles, according to reports from motorists to SCVNews.com.

Numerous additional minor collisions have occurred in the area of the backup, and the CHP is reporting that drivers are turning around and traveling the wrong way to exit the freeway.

Temperatures in Canyon Country at the time were 112 degrees.