shireen adabaki at children's national medical center says it is critical for parents to keep an eyer kids and should never assume a fence or a gate will keep a kid out. her staff saw 21 year drownings in their emergency room alone last year. >> a lot of people put pool covers on the pool. we have seen a few again cases of toddlers suffocating, you know, near drowning in the small amou pool cover. >> reporter: all of the experts we talked to say try to think like a toddler. looking for where they could squeeze through. and tackle the problem now. so you never have to come home to something like this. tisha thompson, news 4 i-team. >> everyone agrees, you should teach a child to swim starting as early as 2 years old. but even teenagers who are able to swim can drown. so tisha and the i-team put together a list of what parents can do to protect their children at the pool. and since the laws vary from county to county, you can also find a list of what pool owners must do to stay safe this summer on our nbc washington app. >>> a vietnam war veteran receives the nation's highest military