• Mayo Clinic Minute: How to tell if someone is drowning

A sunny day at the beach or pool can take a dark turn in seconds.

"Drowning in this country remains one of the leading causes of accidental death in children and affects adults, as well," says Dr. Michael Boniface, a Mayo Clinic emergency medicine physician.

But Dr. Boniface says drowning usually doesn't look how people expect it to.

Watch: The Mayo Clinic Minute

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According to the Centers for Disease Control and Prevention (CDC), on average, more than 10 people die from drowning each day, mostly children. But there isn't usually the splashing and screaming you see in movies.

"In most cases, you don't see a struggle," Dr. Boniface says. "You just see somebody under the water or floating face down."

But, in some cases, there is a window of a few seconds where you might notice some signs.

Drowning people won't wave their arms because their arms instinctively push down to try and get their heads above water. And a drowning person is unable to make any sound, so if a child is noticeably quiet, that's a red flag.

Dr. Boniface says the most important thing you can do is take steps to prevent a drowning. That means limiting alcohol, fencing off a pool and keeping an eye on kids in the water.

"This involves close, constant adult supervision – somebody watching the water at all times," Dr. Boniface says.