Noah Schwebach of Eagle River on Thursday afternoon was one of five people in a Volkswagen GTI Hatchback traveling north on the Sterling Highway.
The small car passed a southbound truck, and a volleyball-size rock rolled off the larger vehicle. The rock smashed the windshield of the car, struck the boy, who was seated in the middle of the back seat, and bounced out of the car.
The boy died at the scene.
The reconstruction project covers 21 miles (34 kilometers) of highway on the Kenai Peninsula. The peninsula's wildlife, mountains and ocean views draw thousands of out-of-state and Alaska visitors each summer. The peninsula is home to the Kenai River, one of Alaska's most popular road-accessible fishing destinations.
Alaska State Troopers said Friday they had tentatively identified the truck and driver but did not immediately release the operator's name.
The speed limit in the construction zone between highway miles 58 to 79 was 55 mph (88.5 kph).
The company working on the road reconstruction, Granite Construction, is cooperating with their investigation and stopped work after the child's death, troopers said.
The investigation will focus on what the truck was hauling and attempt to determine the circumstances of the accident, troopers said. They are seeking additional witness testimony.
The state medical examiner will conduct an autopsy.
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