Wailing and tugging her hair in anguish, Siheang Lim kept vigil all day on the bank of the rain-swollen Calaveras River, where one son drowned and two others may have perished.

"She's sitting up there and she won't leave, poor little thing. I can't blame her," neighbor Diana Husted said Thursday.Lim's boys were among five children - two sets of brothers - who were swept into the chilly current Wednesday evening while playing. Holding hands, the youngsters apparently thought they could wade to an island in the middle of the stream, police said.

One child, 10-year-old Sitha Soun, was rescued immediately by a bystander, who saw the children tumble into the water. But the onlooker was unable to reach the other four children, who disappeared.

Three hours later, police found the body of Vanna Soun, 9. Thursday morning, a police officer walking the bank a half-mile downriver spotted the body of Charles Pich, 7, a son of Siheang Lim.

Rescuers hunted through the night for her two other sons, 9-year-old Herbert Pich and his 8-year-old brother, Danalee.

Police didn't know why the mother's name differs from her sons.