The body of one of the missing boys, 15-year-old Clyde Shimanski III, was recovered Tuesday afternoon.
Witnesses say he and his friend, 14-year-old Nick Cianciotto, were riding their bikes on the lake when the ice cracked below them.
The boys' screams brought help, but rescuers were unable to locate the pair in the darkness.
Acting Morris County Prosecutor Fredric Knapp said state police dive teams used sonar to try and locate the bodies and were on the bottom the for two and a half hours Tuesday.
Speaking at a news conference, Mayor Greenbaum said the entire town is grieving with the two families.
"It's a terrible thing to have to deal with situations where there are families that don't know where their children are or possibly don't know what's happened to them," he said. "So it's troubling."
Schimanski's father, Clyde Jr., told Eywitness News that his son may have died making his own rescue attempt.
"Clyde was out there, and he seen the kid go through the ice," he said. "And Clyde went to save him on his bicycle. And then they both went in. And then people on the shore heard them screaming. He was a very good child. I'm going to miss him a lot."
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