A man drowned after wading into a lake at a historic amusement park, the third fatality at the park in as many years, authorities said.

Won Yong Kim, of Queens, was celebrating July Fourth at Playland Amusement Park with his wife and 5-year-old son Tuesday when he waded into the man-made lake and began struggling in the water, said Westchester County Public Safety Commissioner Thomas Belfiore.

Kim, 43, was removed from the lake, which is off-limits to swimmers, and was pronounced dead about an hour later at a hospital.

Park director Dan McBride said authorities did not know why Kim waded into the water. The lake should be marked with "no swimming" signs, but officials said park visitors sometimes take them down.

The lake, about 40 feet deep at its center, is used by paddle boaters and kayakers, said Westchester County Deputy Parks Commissioner Monty Long.

In 2004, a 7-year-old girl died after falling from the park's Mind Scrambler ride. Investigators concluded the girl had wriggled free of a restraining bar and fell soon after it started.

A 7-year-old boy was killed last year when he climbed out of his boat ride and fell, dying instantly from blunt head trauma, according to investigators.

The county-owned Playland, which opened in 1928, is a National Historic Landmark. Rye is about 30 miles northeast of New York City.