HOUSTON -- A grandfather was jailed Saturday after he took his two grandchildren to the park and returned with only one of them. His 5-month-old grandson was found Friday night all alone in a park outside Collins Elementary School in southwest Houston.

Yvette Diallo said her father, Roy Garza, 54, was left in charge of her children while she went to work and her husband was asleep.

When she left the house, her father was cooking breakfast for the children and seemed fine.

She said her father took her 2-year-old daughter Kayla and grandson Alpha for a walk, but he only came home with Kayla.

"He was drunk. He was drunk. I know he was drunk," Diallo said.

Yvette said her dad first told her that he didn't take Alpha to the park and then told her that he could not remember what happened.

"I'm very disappointed at my dad because no matter what, he was responsible for them," Diallo said. "He was responsible for my kids and he's never done anything like this ever."

Alpha was found several hours later.

Diallo said she is heartsick and has only one wish.

"Please give me back my baby," she pleaded.

The mother of two said the past couple of days have been like a bad dream.

First, she dealt with the sinking feeling of not knowing where to find her baby.

Then, when she heard that he was OK, she was told that she could not see him and that he was being sent to a foster home.

"I don't know (how this could happen)," Diallo said. "I wish I could ask him why or what happened. I don't know."

Now, the family will have to answer to investigators with Child Protective Services.

"We want to continue our investigation," said CPS spokeswoman Gwen Carter. "We want to understand what happened, so we can make sure this child is safe."

For now, Diallo can only hold her pictures. She has no idea when she'll see her baby boy again.

"You never think something like this is going to happen," Diallo said. "I want to see him now."

Garza was charged with a felony -- endangering a child.

A court date has been set for 9 a.m. Monday in family court.