THE BRONX - Tuesday marked the first full day of summer, and children were out at the city’s pools and beaches.

Summer fun can turn dangerous if parents aren't aware of swimming children, according to the Bronx YMCA's aquatics director.

Nadia Arroyo says that a child can begin to drown within 10 seconds.

She says the most important thing is for parents to always watch their kids in the water, even when there's a lifeguard on duty.

Parents should also remain within reach, because even children who know how to swim can have accidents.

If children don't know how to swim, they should only be in chest-deep water or less.

Arroyo also recommends swimming lessons for all children.