One such incident occurred this month in Miami when a 4-year-old girl drowned when her arm got sucked into the pool's drain. She was rescued by her mother, but this type of thing actually happens more often than you think.
There have been dozens of similar incidents across the country. Now a new federal law scheduled to take effect in December is supposed to prevent those drownings. But as 7 On Your Side found out, that federal law may not be enforced in California. The thought of that hurts a Mariposa couple who will never forget what happened to their son.
"He was a good kid," says mother Sue Maroney.
"He was fun-loving, good-natured," says father Bruce Maroney.
TJ Maroney died almost 11 years ago doing what he enjoyed doing most -- swimming.
TJ was in the water at the San Benito County Fairgrounds when his arm got sucked into a swimming pool drain, trapping him underwater. The grate of the drain TJ got sucked into had been left off while repairs were being done.
Swimming is still a big part of TJ's parents' life. When 7 On your Side visited with Bruce and Sue Maroney, their grandchildren were in the backyard pool.
What happened to TJ still haunts Bruce and Sue, especially on his birthday and the day he died.
"It's hard before and after those days every year, but we have his memories," says Sue.
TJ is one of at least 35 children who have died in similar accidents since 1984. The Consumer Product Safety Commission says another 100 children have been seriously injured.
In 2004, an 8-year old Sacramento area girl drowned in a pool when her hair became entangled in the pool's drainage system. One year later, a 3-year-old Southern California boy backed his buttocks onto the drain of a spa.
"It sucked me in," says young Ryan Kotschedoff from Mission Viejo.
He survived, but the force of the suction was strong enough to remove eight inches of his bowel.
"So a child's buttocks fit right there and seal it off. And with that pressure building up to 500 pounds of force, in a matter of time, it will then pull all at once the intestines out of the anus of the child," says Paul Pennington with the Pool Safety Consortium.
Pennington of Santa Rosa helped 7 On Your Side demonstrate just how strong 500 pounds of force can be.
"So what happened is I took a wig which represented a full head of female's hair. When I set it down, the suction force on that drain was enough to matte it all the way down. And as you saw in the picture, I let go of it. It was being held down on its own," says Pennington.
"Your hair just kind of blows out when you're in the water. You've all seen those pictures. My hair would get to the point where if I got too close in there, it could definitely get pulled in," says Dean Peterson, director of San Mateo County's Department of Environmental Health.
The Virginia Greame Baker Pool and Spa Safety Act will go into effect in December. It requires all pools at hotels, apartment, clubs and other public facilities to have federally approved anti-entrapment drain covers. Currently, only new pools or pools being renovated are required to have those drain covers.
The act is named after the granddaughter of former Secretary of State James Baker. She drowned after sitting on a flat drain cover on the bottom of a pool.
7 On your Side found one of those covers at a Days Inn in Redwood City. Pennington immediately notified the hotel of what we found. The manager promised to look into replacing it.
"We have a pool service here, right. We want to consult them. We need to check what we can do," says Sam Uppala from Days Inn.
But the Days Inn wasn't the only place we found a problem. We randomly inspected the pools of nine hotels in San Mateo County. All nine of them had issues -- either drains covers that must be changed or automatic shutoff valves that must be installed by December.
A similar survey by ABC News' Brian Ross found drain covers cracked, rusted and easily removable by children.
The new safety act also requires pools with only one main drain to have a system that automatically shuts that drain off when it becomes plugged.
That's something the Maroneys say would have saved their son.
"If they would have had them at that time, our son would have been alive," saiys Bruce Maroney.
Peterson supports the new safety act and is urging the state to adopt the measure as well. Sources with the federal government, county government and pool industry all say the state has yet to do that.
"It is my understanding it's resources, resources both in money and personnel," says Peterson.
Counties technically can't begin enforcing the new federal regulations until the state adopts it.
But Santa Clara County's Department of Environmental Health isn't waiting. Seventy percent of the hotels the county has surveyed need to make changes by December.
"What we're looking for is some kind of uniform standardization that we could get from the state in terms of some guidance. But lacking that, quite frankly, Santa Clara County will move forward," says Ben Gale with the Santa Clara County Environmental Health.
The Maroneys say the delays by the state in adopting this frustrates them.
"Arnold, you have a child, a couple children, what would it be like without one of them? For a small price, you could stop a lot of the drownings that occur in the pools," says Bruce Maroney
The State Department of Public Health says it's awaiting federal guidelines on possible grants to help implement the new law and will continue to work with the Consumer Product Safety Commission on the issue.