USA data for summer 2013
At least 202 children drowning accidents between Memorial day and Labor day 2013, based on Police and media reports.
At least 143 of them were under 5 years old.
Looking at this in perspective - there are almost 10 million residential swimming pools in the USA, and more than 5 million residential hot tubs.
There are over 74 million children in the USA, out of which more than 24.5 million are under 5 years old.
Also note that:
Children between the ages of 1 and 3 represented 67 percent of reported fatalities and 64 percent of injuries.
• African American children between the ages of 5 and 14 are six times more likely to drown in pools than white and Hispanic children that age, according to the Centers for Disease Control and Prevention.
• Data from USA Swimming indicate that 70 percent of African American children and 62 percent of Hispanic children cannot swim, making them more likely to drown.
So yes - there is a risk. One out of 170,000 children under 5 years of age drowned. And this is in 2013 - after years of an awareness campaign, mandatory pool fences and gates, pool alarms etc.