It is so scary for me. I was crying," Fontenot said.
Her neighbor, James Wilson, raced to the pool.
"I came outside to try to do what I could," Wilson said.
An 8-year-old girl had already been pulled out of a pool at the Avalon Bay Apartments by a maintenance worker.
"The guy had a girl on the ground over there and she was unresponsive, and I know she had a brother with her, and I was like 'Where is the brother?' and she couldn't talk," he said.
The 6-year-old brother was still in the pool.
"He was on the bottom of the pool, all the way on the bottom," explained Wilson.
Wilson says he jumped in.
"I just hopped the gate and dove in and got him at the bottom of the pool. I tossed him out of the pool and I got out and tried to administer CPR, but couldn't get a response," Wilson said.
"I kept working until the professionals came," he said.
When police arrived, they had to cut the padlock off the gate to get to the kids.
"We saw the police trying to bring him back to life and he wasn't responding. He didn't have a pulse or anything," said an eyewitness.
Sadly, police say the boy died at the hospital.
Investigators say the brother and sister were at the pool unsupervised.
"They were dropped off here at the complex with a relative and somehow made their way over here to this complex to get in the pool," says Lt. Steve Dorris of Baytown Police.
The little girl is expected to be okay.
Investigators say they now want to find out who was supposed to be watching the kids.
"We want to know how those children got separated from the person who is supposed to be watching them and where was that person at the time," said Lt. Dorris.
SKYEYE13: Above the scene where children were found