Story highlights The mother has been arrested on murder, manslaughter charges

Jillian Meredith McCabe, 34, held with bail set at $750,000

The Yaquina Bay Bridge is more than 100 feet above the water

Woman told police she threw her son off the bridge, police say

A 6-year-old boy was found dead in the frigid waters of Oregon's Yaquina Bay after his mother told police she threw him off a bridge Monday evening, authorities said.

The body of London McCabe was found in the water about a mile from the Yaquina Bay Bridge about 10:20 p.m., roughly four hours after his mother called 911 to say she'd thrown him from the span, Newport police said.

The mother, Jillian Meredith McCabe, 34, was arrested on charges of aggravated murder, murder and first-degree manslaughter, police said.

Jillian McCabe

McCabe, of nearby Seal Rock, called police around 6:30 p.m. Monday "saying she threw her child over the side," Newport Police Chief Mark Miranda said.

The water of Yaquina Bay is more than 100 feet below the bridge. Chances of survival from a fall that high were "minimal," Miranda said.

Even if a person survived the fall, the chief said, one could survive the frigid water for only about 20 minutes.

Police have not commented on the cause of the boy's death or a possible motive.

McCabe was being held at the Lincoln County jail Tuesday morning with bail set at $750,000.

Two boats and a Coast Guard helicopter searched the water for hours before the body was found, Coast Guard spokesman Jonathan Klingenberg told CNN.