After a 2-year-old girl drowned and a 6-year-old boy nearly drowned just two hours apart and within a few miles from each other, officials are calling on parents and others to keep close tabs on children near the water.

"We all need to be there for the keiki," said Shayne Enright, spokes­woman for Hono­lulu’s Emergency Services Department. "The community has got to step up and step in, even if it is not their child."

In both cases Monday the children got into trouble while their parents weren’t paying attention, in areas where there are no lifeguards, one at Sand Island and the other at Kaka­ako Waterfront Park.

"Swim where there is a lifeguard," Enright said. "Never turn your back on a child. Never leave a child in the responsibility of another child. They don’t know what to do, and they are not strong enough to pull a child from under the water."

Drowning is the leading cause of injury-related death among children ages 1 to 5 in Hawaii, accounting for one-third of victims, according to Dan Galanis, epidemiologist with the Department of Health’s Injury Prevention and Control Program.

Over the past five years, 12 children ages 1 to 5 drowned in the state, Health Department data show. Five of them died in the ocean, four in swimming pools and three in bathtubs.

On Monday the 2-year-old either walked into the water or fell off a pier at Sand Island while her mother was in the restroom during a family gathering near the Hono­lulu Community College Marine Education Training Center, Enright said.

"It’s unclear if anyone was watching her at that point," Enright said.

The child drifted 50 yards offshore before being picked up by a boater and was rushed to the hospital at 4 p.m. in extremely critical condition. The Medical Examiner’s Office identified her as Melisa Mizu­tani of Wai­pahu and concluded her death was an accidental drowning. Police classified it as an unattended death.

The 6-year-old boy had been left in the care of a 10-year-old girl at a popular swimming spot at Kaka­ako Waterfront Park, where rock walls create a breakwater. The adults apparently were in a pavilion farther down the promenade while the children were playing in the water when an onlooker saw the boy struggling at about 6 p.m.

"Somehow he got pushed off the ledge by a wave and was taken under," Enright said. A man pulled the boy out of the water, and another person carried him to the parking lot, she said.

"He still had a pulse," Enright said. "No one could tell us how long he was underwater. He was in respiratory distress."

He was taken in critical condition to Kapiolani Medical Center for Women & Children, but no update on his status Tuesday was available because of privacy laws.

Children of all ages were frolicking in the clear, deep water at the same spot at the Kaka­ako park Tuesday, including little ones in inflatable rings. Schools are on fall break this week.

"I always keep the younger ones close to me," said Tyler Yuen, a burly man holding tightly to a little boy’s hand as they headed up the slippery stairs from the ocean to the showers.

There were 79 drownings in Hawaii in 2011, most of them in the ocean. About half of the victims lived in Hawaii, and the rest were visitors. The vast majority were adults. Nonetheless, drowning accounts for more deaths among children ages 1 to 5 in Hawaii than any other cause, including cancer, motor vehicle crashes or homicide, Galanis said.

"The take-home message is careful supervision of young children around any type of water environment," Galanis said, "including around and inside the home."