Charlotte McCue and her family were on vacation with grandparents when a second boat slammed into their boat on Lake George around 9:30 p.m.
The girl was killed in the collision and her mother was taken to the hospital in critical condition.
Alex West was driving the 21-foot Larson powerboat that struck the family, authorities said. Alex and four passengers reportedly left the scene without calling for help. Investigators are determining whether charges will be filed against West.
Neighbors in Carlsbad are stricken with grief for their long-time friends.
“This community is there for them… all we are thinking about is their well-being," said family friend Gary Clough. "They are wonderful people”