DENVER -- A 2-year-old Denver boy was in the hospital Sunday night, after he almost drowned in an apartment pond.

It happened Sunday morning at The Lakes of Monaco Pointe Apartments in East Denver.

The boy's parents say they walked away for just a few minutes while he was playing outside, and he ran off.

On the other side of the complex, police say a Good Samaritan was walking his dog and noticed the boy floating in a pond that weaves through the complex. The man pulled the boy out and gave him CPR.

The boy’s mother, Julia Khamis, said she's learned a lesson that other parents need to remember this summer.

"They just need to keep their eyes on their kids," she said. "Wherever they're going, I have to just follow them."

Drowning is the second leading cause of death of children under the age of four, after car accidents.