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Calif. mother arrested for allegedly throwing 7-month-old off parking structure

This image provided by the Orange Police Department shows Sonia Hermosillo who was arrested Monday Aug. 22, 2011. AP Photo/Orange Police Department

(CBS/AP) ORANGE, Calif. - A California mother was arrested early Tuesday after police say she tossed her 7-month-old son from the fourth-floor of a parking structure at Children's Hospital of Orange County.

Sonia Hermosillo, 31, of La Habra was arrested on suspicion of attempted murder and is being held without bail, police say.

Authorities were notified of the incident when a witness called 911 after seeing the baby falling around 6 p.m. Monday. Surveillance video shows Hermosillo's Chevrolet Blazer SUV with an empty child restraint seat leaving the parking structure a short time later, police said.

The female driver was the only person inside the SUV and the license plate was traced to the Hermosillo home.

Police say that the boy's father reported Monday evening that his wife, Sonia Hermosillo, and their son were missing.

An Orange police officer driving past Children's Hospital at 10:15 p.m. spotted the Blazer. The SUV was stopped and Hermosillo was detained for questioning, then arrested.

The infant remains in critical condition at University of California, Irvine, Medical Center, police say.