Two others were fighting for their lives after a total of five children aged between three and eight were discovered unconscious in the water yesterday, having apparently been left unsupervised.
The pond is located close to a cheap hotel on an industrial estate near Saint-Ouen-l'Aumone on the northeastern outskirts of Paris.
The children were from three different families and were temporarily in care while their single mothers underwent psychological treatment.
Police were called by a hotel employee who was alerted by another child.
Mickael Flour, who lives with his family in a caravan close to the pond, said children often played by the water.
"They like to throw sticks and stones," he told AFP. "We would often tell them, don't go down there, it's dangerous."
Another local, Sylviana Ternus, 29, added: "The children were often on their own, with no adult.
