ESCONDIDO, Calif. -- Authorities Tuesday identified a 52-year-old San Diego woman who was killed in a North County freeway pileup that shut down a stretch of the regional route during morning rush hour.

Caroline McElhaney was fatally injured in the crash that occurred on Interstate 15 in Escondido shortly before 6:30 a.m. Monday, according to the San Diego County Medical Examiner's Office.

According to the California Highway Patrol, the driver of a southbound 1999 Dodge Ram encountered stationary traffic ahead of him while changing lanes near Ninth Avenue. He was apparently unable to stop in time to keep from rear-ending McElhaney's Mercedes-Benz.

The impact pushed the 2001 Mercedes into the back end of a Toyota Avalon, which in turn smashed into a Toyota Sienna, CHP public affairs Officer Eric Newbury said.

Medics took McElhaney and three other injured people to Palomar Medical Center, where McElhaney was pronounced dead. Although the CHP initially reported that McElhaney lived in Vista, the county medical examiner's office Tuesday morning said she lived in San Diego with her husband.

She died less than two weeks shy of her next birthday, according to the medical examiner's office.

The drivers of the Toyotas and a man who had been riding in the Sienna were treated for minor injuries. The driver of the pickup truck, 28-year-old Jackson Redmond of Colton, did not require hospital treatment.

The entire southbound side of the freeway was closed for about an hour to allow for cleanup and investigation, Newbury said.