A Georgetown toddler is dead, just six months after Child Protective Services returned him and his two siblings home.

Georgetown police will only say that it is an open investigation and no one has been arrested.

One neighbor, who didn't want to be identified, said authorities surrounded their trailer in North Georgetown last week.

"There was tape all around the RV. They had crime scene investigators all around taking pictures inside and out. Just standing here talking. They were out here for a couple hours," the neighbor said.

According to an affidavit, 21-month-old Christopher Barcenas was rushed to Dell Children's Medical Center last Thursday.

His mother, Elizabeth Arellano, 21, said the toddler was eating a chicken nugget, and when she came back, he was not breathing.

But doctors say he had a large skull fracture to the back of his head, which was consistent with a combination of blunt force trauma and shaking.

"They seemed like a happy family," said Rebecca Ramirez, lives nearby. "They were always having barbecues out there."

But Child Protective Services starting responding to calls -- in September 2006 -- just one week after Barcenas and his twin brother were born.

In February 2007, CPS removed the twins and their older sister. In December 2007, after the parents completed parenting classes and counseling, the children were returned.

CPS continued welfare checks through March 2008.

On April 9 2008, CPS was dismissed. Seven weeks later, Barcenas was dead, and the other two children are now back in protective custody.

Medical staff did find suspicious bruises on the chest of the other twin brother. That's still being investigated.

The mother in this case is seven months pregnant.