A woman accused of dropping her three children to their deaths in the chilly waters of San Francisco Bay (search) was arrested while pushing an empty stroller away from the pier and was jailed Thursday on suspicion of murder.

Lashaun T. Harris, 23, was taken into custody Wednesday night after someone saw her drop the youngsters from a 10-foot pier not far from Fishermen's Wharf (search), a major tourist spot.

The San Francisco Chronicle (search) reported that the woman told authorities that voices had told her to throw her children in. And 16-year-old Britney Fitzpatrick, who said she is the woman's half-sister, said Harris talked to herself and was diagnosed with schizophrenia this year.

"She told my mama she was going to feed them to the sharks," Britney said of the children. "No one thought it was that serious."

Harris first took off the children's clothes before dumping them in the water, according to a report in The San Jose Mercury News.

The body of Taronta Greely Jr., 2, was recovered late Wednesday near a yacht club, about two miles from the pier. The Coast Guard continued to search on Thursday for the other youngsters, Trayshaun, 6, and Joshua, 16 months.

"All of us are in shock," Mayor Gavin Newsom (search) said. "This is a senseless and unexplainable act that goes beyond the pale. Frankly, it makes you sick to your stomach."

Harris had been living with her children in a Salvation Army shelter in Oakland and had no criminal record in San Francisco, police said. She was jailed on suspicion of three counts of murder and three of assault.

"I just talked to her yesterday," Mary Ann Ramirez, the shelter's social services manager, told the Chronicle on Wednesday. "We had our usual, `How are you doing, how's the kids?' I would never have guessed in a million years that today she would do that."

Asia Powell, who identified herself as Harris' cousin, told KPIX-TV that Harris was taking medication for a mental illness.

"I know that she would never hurt her kids," Powell said. "I know that."

Fitzpatrick and about a dozen other family members met at Pier 7 midday Thursday. They got out of a van and held hands and prayed.

Most declined to comment, but Avery Garrett, who identified himself as a family spokesman, told The Associated Press that Harris' family had previously tried to get her into a mental hospital, but the hospital refused to admit her.

"We knew the girl needed help," he said.

It was not immediately known whether Harris had an attorney.