Robin Tarr wishes she had known in 2008 what she knows now.

“Don't underestimate your kids,” she said.

Tarr wants to share her son’s story, hoping to prevent the same tragedy from happening to anyone else.

“August 10, 2006 is when he was born and he passed away July 20, 2008,” she said.

That's when 23-month-old Luis Garcia drowned in the family’s fenced backyard pool.

RELATED: What to do in a drowning situation

“He let himself in the pool by climbing up on a chair, reaching through the door and grabbing a string that was hanging on the lock and pulled that door open,” she said.

One out of every 10 drownings happens after a child figures out how to get through a pool fence, according to the Consumer Product Safety Commission.

RELATED: Operation: Water Watch resources

"He watched his dad open that gate many times and saw him pull that string and he learned how to do it without him realizing that he did it until it was too late," Tarr said. "It only takes a few seconds for a child to go under and drown and people think that it's really loud and they'll hear their child. Well, they won't. They slowly and quietly sink under the water and they don't make a noise. So they could be gone in an instant and you could be standing right there."

Layers of protection are needed to prevent drownings. Alarms on doors and fences that lead to a pool is one extra layer that could be life saving. For more tips, click here.